| | English Name | Japanese Name | Castle Type | Castle Condition | Historical Period | Prefecture | Year Visited | AddedJcastle | dec |
|---|
| Aburakawa Nobue Yashiki | Aburakawa Nobue Yashiki | 油川信恵屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Ahoyama Castle | Ahoyama Castle | 青山城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | 2024 | 2024 | |
| Aida Yakata | Aida Yakata | 会田館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Aika Yashiki | Aika Yashiki | 秋鹿屋敷 | Fortified Manor | Ruins only | Edo Period | Shizuoka Prefecture | Viewer Contributed | 2025 | |
| Aiki Castle (Minochi) | Aiki Castle (Minochi) | 相木城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Aimiyamamonomi Fort | Aimiyamamonomi Fort | 逢見山物見砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Ainuta Fort | Ainuta Fort | 相垈塁 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Aizu Wakamatsu Castle | Aizu Wakamatsu Castle | 会津若松城 | Hilltop | Reconstructed main keep | Edo Period | Fukushima Prefecture | 1997
1998
2003
2011 | 1999 | |
| Akagi Kita Castle | Akagi Kita Castle | 赤木北城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Akagi Minami Castle | Akagi Minami Castle | 赤木南城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Akagi Yakata | Akagi Yakata | 赤木館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Akahori Castle (Ise) | Akahori Castle (Ise) | 伊勢赤堀城 | Fortified Manor | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2025 | |
| Akaiwa Castle | Akaiwa Castle | 赤岩城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2025 | |
| Akasaka Jin'ya | Akasaka Jin'ya | 赤坂陣屋 | Fortified Manor | No main keep but other buildings | Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Akashi Castle | Akashi Castle | 明石城 | Hilltop | No main keep but other buildings | Edo Period | Hyogo Prefecture | 2009
2024 | 2007 | |
| Akashibu Castle (Mikawa) | Akashibu Castle (Mikawa) | 三河赤渋城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Akasu Castle (Ina) | Akasu Castle (Ina) | 伊那赤須城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Akatsuka Castle | Akatsuka Castle | 赤塚城 | Hilltop | Ruins only | Pre Edo Period | Tokyo | 2019 | 2020 | |
| Akayama Jin'ya | Akayama Jin'ya | 赤山陣屋 | Flatland | Ruins only | Edo Period | Saitama Prefecture | 2023 | 2023 | |
| Akazawa Yakata | Akazawashi Yakata | 赤沢氏館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Akechi Castle | Akechi Castle | 明智城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2025 | |
| Akechi Jin'ya | Akechi Jin'ya | 明智陣屋 | Hilltop | Ruins only | Edo Period | Gifu Prefecture | Viewer Contributed | 2025 | |
| Akechi Osayama Castle | Akechi Osayama Castle | 明智長山城 | Mountaintop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2021 | |
| Aki Castle | Aki Castle | 安芸城 | Hilltop | Ruins only | Pre Edo Period | Kochi Prefecture | Viewer Contributed | 2013 | |
| Akiba Fort (Azumi) | Akiba Fort (Azumi) | 安曇秋葉砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Akiba Fort (Ina) | Akiba Fort (Ina) | 伊那秋葉砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Akita Castle | Akita Castle | 秋田城 | Flatland | No main keep but other buildings | Pre Edo Period | Akita Prefecture | 2018 | 2012 | |
| Akiyama Yakata | Akiyama Yakata | 秋山館 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Akiyoshi Fort | Akiyoshi Fort | 秋吉砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Akizuki Castle | Akizuki Castle | 秋月城 | Flatland | No main keep but other buildings | Edo Period | Fukuoka Prefecture | Viewer Contributed | 2009 | |
| Akizuki Domain South Detached Palace | Akizuki Domain South Detached Palace | 秋月藩南御殿 | Flatland | Ruins only | Edo Period | Fukuoka Prefecture | Viewer Contributed | 2020 | |
| Ako Castle | Ako Castle | 赤穂城 | Flatland | No main keep but other buildings | Edo Period | Hyogo Prefecture | 2018 | 2009 | |
| Akozu Castle | Akozu Castle | 赤尾津城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Akita Prefecture | Viewer Contributed | 2016 | |
| Akutagawasan Castle | Akutagawasan Castle | 芥川山城 | Mountaintop | Ruins only | Pre Edo Period | Osaka | 2016
2022 | 2013 | |
| Amabiki Castle | Amabiki Castle | 雨引城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Amaga Castle | Amaga Castle | 天ヶ城 | Mountaintop | Reconstructed main keep | Pre Edo Period | Miyazaki Prefecture | Viewer Contributed | 2012 | |
| Amagasaki Castle | Amagasaki Castle | 尼崎城 | Flatland | Reconstructed main keep | Edo Period | Hyogo Prefecture | 2013 | 2013 | |
| Amagata Castle | Amagata Castle | 天方城 | Mountaintop | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2025 | |
| Amanari Castle | Amanari Castle | 雨鳴城 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Amari Yakata | Amari Yakata | 甘利館 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Amemiya Yashiki | Amemiya Yashiki | 雨宮屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Ametoya Castle | Ametoya Castle | 雨戸屋城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Amidadou Castle (Omi) | Amidadou Castle (Omi) | 近江阿弥陀堂城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Amidagamine Castle (Yamashiro) | Amidagamine Castle (Yamashiro) | 山城阿弥陀ヶ峰城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | Viewer Contributed
2022 | 2022 | |
| Amino Shingozaemon Yashiki | Amino Shingozaemon Yashiki | 網野新五左衛門屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Amino Yashiki | Amino Yashiki | 網野屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Anjou Jin'ya | Anjou Jin'ya | 安城陣屋 | Flatland | Ruins only | Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Annaka Castle | Annaka Castle | 安中城 | Hilltop | No main keep but other buildings | Edo Period | Gunma Prefecture | 2018 | 2018 | |
| Ano Yakata | Ano Yakata | 阿野館 | Fortified Manor | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2023 | |
| Anrakuji Yakata | Anrakuji Yakata | 安楽寺館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Ansho Castle | Ansho Castle | 安祥城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | 2009 | 2009 | |
| Anshouko Castle | Anshouko Castle | 安祥古城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Aoiyama Castle | Aoiyama Castle | 青井山城 | Mountaintop | Ruins only | Pre Edo Period | Fukui Prefecture | Viewer Contributed | 2023 | |
| Aoki Castle (Azumi) | Aoki Castle (Azumi) | 安曇青木城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Aoki Castle (Sakata) | Aoki Castle (Sakata) | 近江坂田青木城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Aono Castle (Mikawa) | Aono Castle (Mikawa) | 三河青野城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Aoyagi Castle | Aoyagi Castle | 青柳城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Nagano Prefecture | 2015 | 2016 | |
| Aoyagi Yakata | Aoyagi Yakata | 青柳館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Aoyama Castle | Aoyama Castle | 青山城 | Mountaintop | Ruins only | Pre Edo Period | Saitama Prefecture | 2015 | 2015 | |
| Aoyama Castle (Nagato) | Aoyama Castle (Nagato) | 長門青山城 | Mountaintop | Ruins only | Pre Edo Period | Yamaguchi Prefecture | Viewer Contributed | 2021 | |
| Aoyama Castle (Omi) | Aoyama Castle | 青山城 | Hilltop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2021 | |
| Aoyama Yashiki (Mikawa) | Aoyama Yashiki (Mikawa) | 三河青山屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Ara Castle (Ina) | Ara Castle (Ina) | 小出荒城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Ara Castle (Murakami Clan Fort Network) | Ara Castle (Murakami Clan Fort Network) | 村上荒城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Aragaito Fort | Aragaito Fort | 荒海渡砦 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Arahorinaiki Yashiki | Arahorinaiki Yashiki | 荒堀内記屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Arai Castle | Arai Castle | 荒井城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Araihara Castle | Araihara Castle | 荒井原城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Araino Castle (Mikawa) | Araino Castle (Mikawa) | 三河荒井野城 | Hilltop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Arako Castle | Arako Castle | 荒子城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2020 | |
| Arashi Castle | Arashi Castle | 嵐城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Aratame Castle | Aratame Castle | 新田目城 | Flatland | Ruins only | Pre Edo Period | Yamagata Prefecture | Viewer Contributed | 2023 | |
| Arato Castle | Arato Castle | 荒砥城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Nagano Prefecture | 2008 | 2008 | |
| Aratoshou Castle | Aratoshou Castle | 荒砥小城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Arayama Castle | Arayama Castle | 荒山城 | Mountaintop | Ruins only | Pre Edo Period | Ishikawa Prefecture | Viewer Contributed | 2019 | |
| Arikoyama Castle | Arikoyama Castle | 有子山城 | Mountaintop | Ruins only | Pre Edo Period | Hyogo Prefecture | 2013 | 2013 | |
| Aruga Castle | Aruga Castle | 有賀城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Asaba Castle | Asaba Castle | 麻場城 | Mountaintop | Ruins only | Pre Edo Period | Gunma Prefecture | 2015 | 2016 | |
| Asada Castle (Chikuma) | Asada Castle (Chikuma) | 筑摩浅田城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Asahara Yakata | Asahara Yakata | 浅原館 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Asahi Castle (Chikuma) | Asahi Castle (Chikuma) | 筑摩旭城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2019 | |
| Asahi Castle (Minochi) | Asahi Castle (Minochi) | 水内旭城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Asahi Castle (Owari) | Asahi Castle (Owari) | Owari-Asahijō | Mountaintop | Reconstructed main keep | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2019 | |
| Asahi Moated Settlement | Asahi Moated Settlement | 朝日環濠集落 | Flatland | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Asahiyama Castle | Asahiyama Castle | 旭山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Asahiyama Castle (Kai) | Asahiyama Castle (Kai) | 甲斐旭山城 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Asaka Castle (Chikuma) | Asaka Castle (Chikuma) | Chikuma-Asakajō | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Asakura Yakata | Asakura Yakata | 朝倉館 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Fukui Prefecture | 2023 | 2023 | |
| Asama Palace | Asama Palace | 浅間御殿 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Asama Yakata | Asama Yakata | 浅間館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Asano Castle | Asano Castle | 浅野城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2025 | |
| Ashigara Castle | Ashigara Castle | 足柄城 | Mountaintop | Ruins only | Pre Edo Period | Shizuoka Prefecture | 2010 | 2010 | |
| Ashikaga Masauji Yakata | Ashikaga Masauji Yakata | 足利政氏館 | Fortified Manor | Ruins only | Pre Edo Period | Saitama Prefecture | 2023 | 2023 | |
| Ashikagashi Yakata | Ashikagashi Yakata | 足利氏館 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Tochigi Prefecture | 2007 | 2007 | |
| Ashimori Jin'ya | Ashimori Jin'ya | 足守陣屋 | Flatland | No main keep but other buildings | Edo Period | Okayama Prefecture | Viewer Contributed | 2022 | |
| Ashinoya Jin'ya | Ashinoya Jin'ya | 芦谷陣屋 | Flatland | No main keep but other buildings | Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Asonuma Castle | Asonuma Castle | 阿曽沼城 | Flatland | Ruins only | Pre Edo Period | Tochigi Prefecture | 2017 | 2017 | |
| Asou Castle (Mikawa) | Asou Castle (Mikawa) | 三河麻生城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Asouko Castle (Mikawa) | Asouko Castle (Mikawa) | 三河麻生古城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Asukayama Castle | Asukayama Castle | 飛鳥山城 | Hilltop | Ruins only | Pre Edo Period | Tokyo | 2021 | 2022 | |
| Asuke Castle | Asuke Castle | 足助城 | Mountaintop | Reconstructed main keep | Pre Edo Period | Aichi Prefecture | 2019 | 2017 | |
| Asuke Jin'ya | Asuke Jin'ya | 足助陣屋 | Flatland | Ruins only | Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Atagoyama Noroshidai | Atagoyama Noroshidai | 愛宕山烽火台 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Atsushiba Yashiki (Koma) | Atsushiba Yashiki (Koma) | 巨摩厚芝屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Awaji Castle (Chikuma) | Awaji Castle (Chikuma) | 筑摩淡路城 | Fortified Manor | Ruins only | Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Awaya Yakata | Awaya Yakata | 粟屋館 | Fortified Manor | Ruins only | Pre Edo Period | Fukui Prefecture | Viewer Contributed | 2023 | |
| Awazawa Castle (Suwa) | Awazawa Castle (Suwa) | 諏訪粟沢城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Aya Castle | Aya Castle | 綾城 | Mountaintop | Reconstructed main keep | Pre Edo Period | Miyazaki Prefecture | Viewer Contributed | 2007 | |
| Ayukawa Castle (Koka) | Ayukawa Castle (Koka) | 鮎河城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | 2023 | 2023 | |
| Azai Higashi Castle | Azai Higashi Castle | 浅井東城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Azai Nishi Castle | Azai Nishi Castle | 浅井西城 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Azuchi Castle | Azuchi Castle | 安土城 | Hilltop | Ruins only | Pre Edo Period | Shiga Prefecture | 2004
2011
2021 | 2004 | |
| Baba Noroshidai | Baba Noroshidai | 馬場烽火台 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2025 | |
| Baba Yashiki | Baba Yashiki | 馬場屋敷 | Fortified Manor | No main keep but other buildings | Edo Period | Nagano Prefecture | Viewer Contributed | 2019 | |
| Baba Yashiki (Kai) | Baba Yashiki (Kai) | 甲斐馬場屋敷 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Banba Castle | Banba Castle | 番場城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2025 | |
| Beffu Castle (Koka) | Kouka Beffu Castle | 甲賀別府城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2021 | |
| Binmanji Castle | Binmanji Castle | 敏満寺城 | Hilltop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2024 | |
| Bitchu Matsuyama Castle | Bitchu Matsuyama Castle | 備中松山城 | Mountaintop | Original main keep | Edo Period | Okayama Prefecture | 2010
2024 | 2004 | |
| Bitchu Takamatsu Castle | Bitchu Takamatsu Castle | 備中高松城 | Flatland | Ruins only | Pre Edo Period | Okayama Prefecture | Viewer Contributed | 2012 | |
| Biwa Castle (Kai) | Biwa Castle (Kai) | 甲斐琵琶城 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Bizen Date (Uzen) | Bizen Date (Uzen) | 羽前備前館 | Fortified Manor | Ruins only | Pre Edo Period | Yamagata Prefecture | Viewer Contributed | 2023 | |
| Bizenhara Yakata | Bizenhara Yakata | 備前原館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Bodaiyama Castle | Bodaiyama Castle | 菩提山城 | Mountaintop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2025 | |
| Bue Yakata (Totomi) | Bue Yakata (Totomi) | 遠江武衛館 | Fortified Manor | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2024 | |
| Busetsu Castle | Busetsu Castle | 武節城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2022 | |
| Bushihara Fort | Bushihara Fort | 武士原塁 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Chamachi Battery (Obama Domain) | Obama Domain Chamachi Battery | 小浜藩茶町台場 | Flatland | Ruins only | Edo Period | Fukui Prefecture | Viewer Contributed | 2023 | |
| Chausudate | Chausudate | 茶臼館 | Mountaintop | Ruins only | Pre Edo Period | Akita Prefecture | 2020 | 2021 | |
| Chausuyama Castle (Chikuma) | Chausuyama Castle (Chikuma) | 筑摩茶臼山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Chausuyama Castle (Nukata) | Chausuyama Castle (Nukata) | 額田茶臼山城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Chausuyama Castle (Shinano) | Chausuyama Castle (Shinano) | 信濃茶臼山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Chiba Castle | Chiba Castle | 千葉城 | Hilltop | Reconstructed main keep | Pre Edo Period | Chiba Prefecture | 2009 | 2009 | |
| Chifuruya Castle (Sanada) | Chifuruya Castle (Sanada) | 真田千古屋城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Chigasaki Castle | Chigasaki Castle | 茅ヶ崎城 | Hilltop | Ruins only | Pre Edo Period | Kanagawa Prefecture | 2010 | 2009 | |
| Chihaya Castle | Chihaya Castle | 千早城 | Mountaintop | Ruins only | Pre Edo Period | Osaka | Viewer Contributed
2025 | 2014 | |
| Chikaoka Castle | Chikaoka Castle | 近岡城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Chikatou Fort | Chikatou Fort | 千鹿頭砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Chikuma Goten'yama Castle | Chikuma Goten'yama Castle | 筑摩御殿山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Chikusa Castle | Chikusa Castle | 千種城 | Mountaintop | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2024 | |
| Chikuzenbara Fort | Chikuzenbara Fort | 筑前原塁 | Flatland | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Chimura Yashiki | Chimura Yashiki | 千村屋敷 | Fortified Manor | Ruins only | Edo Period | Gifu Prefecture | Viewer Contributed | 2021 | |
| Chinaha Castle | Chinaha Castle | 伊敷索城 | Hilltop | Ruins only | Pre Edo Period | Okinawa Prefecture | | 2024 | |
| Chinen Castle | Chinen Castle | 知念城 | Mountaintop | Ruins only | Pre Edo Period | Okinawa Prefecture | Viewer Contributed | 2023 | |
| Chiran Castle | Chiran Castle | 知覧城 | Hilltop | Ruins only | Pre Edo Period | Kagoshima Prefecture | Viewer Contributed | 2013 | |
| Chofuku Castle | Chofuku Castle | 長福城 | Flatland | Ruins only | Pre Edo Period | Tochigi Prefecture | 2018 | 2018 | |
| Chouja Yashiki (Totomi) | Chouja Yashiki (Totomi) | 遠江長者屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2025 | |
| Choujaike Yakata | Choujaike Yakata | 長者池館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Choujayama Castle | Chojayama Castle | 長者山城 | Hilltop | Ruins only | Pre Edo Period | Ibaraki Prefecture | Viewer Contributed | 2020 | |
| Choujayashiki Yakata | Choujayashiki Yakata | 長者屋敷館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Choukokuji Fort | Choukokuji Fort | 長谷寺砦 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2025 | |
| Chousenji Fort | Chousenji Fort | 長泉寺塁 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Choushouin Yakata | Choshoin Yakata | 長性院館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Chouzenjimae Jin'ya | Chouzenjimae Jin'ya | 長禅寺前陣屋 | Flatland | Ruins only | Edo Period | Yamanashi Prefecture | Viewer Contributed | 2021 | |
| Daikan Yashiki | Daikan Yashiki | 代官屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2025 | |
| Daikan'yama Fort | Daikan'yama Fort | 代官山砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Daikan'yashiki Castle | Daikan'yashiki Castle | 代官屋敷城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2025 | |
| Daikannon Castle | Daikannon Castle | 大観音城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Dainenji Yakata | Dainenji Yakata | 大念寺館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Daita Castle | Daita Castle | 大田城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Daiun'in Doi | Daiun'in Doi | 大雲院土居 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2022 | |
| Damine Castle | Damine Castle | 田峯城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Damine Yashiki | Damine Yashiki | 田峯屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Dannoura Battery | Dannoura Battery | 壇ノ浦台場 | Flatland | Ruins only | Edo Period | Yamaguchi Prefecture | Viewer Contributed | 2021 | |
| Deura Castle | Deura Castle | 出浦城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Do Castle (Mikawa) | Do Castle (Mikawa) | 三河土城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Dodo Fort | Dodo Fort | 百々砦 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Dohiyama Castle (Nagato) | Dohiyama Castle (Nagato) | 長門土肥山城 | Fortified Manor | Ruins only | Pre Edo Period | Yamaguchi Prefecture | Viewer Contributed | 2021 | |
| Doi Castle (Mikawa) | Doi Castle (Mikawa) | 三河土井城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Doi Tono Yashiki | Doi Tono Yashiki | 土肥殿屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2025 | |
| Dokanyama | Dokanyama | 道灌山 | Mountaintop | Ruins only | Pre Edo Period | Tokyo | 2021 | 2022 | |
| Dokyou Castle | Dokyou Castle | 土京城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Dota Castle (Mino) | Dota Castle (Mino) | 美濃土田城 | Mountaintop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2025 | |
| Doudo Castle (Mikawa) | Doudo Castle (Mikawa) | 三河百々城 | Hilltop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Dousawa Fort | Dousawa Fort | 堂沢砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Doushou Hori | Doushou Hori | 道生堀 | Flatland | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Ebe Castle (Omi) | Ebe Castle (Omi) | 近江江部城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Eboshigata Castle | Eboshigata Castle | 烏帽子形城 | Mountaintop | Ruins only | Edo Period | Osaka | 2022 | 2023 | |
| Echizen Katsuyama Castle | Echizen Katsuyama Castle | 越前勝山城 | Flatland | Reconstructed main keep | Edo Period | Fukui Prefecture | Viewer Contributed | 2010 | |
| Echizen Ohno Castle | Echizen Ohno Castle | 越前大野城 | Mountaintop | Reconstructed main keep | Edo Period | Fukui Prefecture | Viewer Contributed | 2007 | |
| Edo Castle | Edo Castle | 江戸城 | Hilltop | No main keep but other buildings | Edo Period | Tokyo | 1992
2001
2003
2004
2011
2012
2013
2014
2015
2016
2017
2018
2019
2022
2023 | 1999 | |
| Egawa Fort | Egawa Fort | 江川砦 | Mountaintop | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2021 | |
| Eimeiin Fort | Eimeiin Fort | 永明院塁 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Ema Yakata | Ema Yakata | 江馬館 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2019 | |
| Enryakuji | Enryakuji | 延暦寺 | Mountaintop | No main keep but other buildings | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Enryakuji Amidadou Fort | Enryakuji Amidadou Fort | 延暦寺阿弥陀堂砦 | Mountaintop | No main keep but other buildings | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Enryakuji Higashitani Fort | Enryakuji Higashitani Fort | 延暦寺東谷砦 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Enryakuji Joudoin Fort | Enryakuji Joudoin Fort | 延暦寺浄土院砦 | Mountaintop | No main keep but other buildings | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Enryakuji Kitatani Fort | Enryakuji Kitatani Fort | 延暦寺北谷砦 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Enryakuji Monjurou Fort | Enryakuji Monjurou Fort | 延暦寺文殊楼砦 | Mountaintop | No main keep but other buildings | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Enryakuji Nishitani Fort | Enryakuji Nishitani Fort | 延暦寺西谷砦 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Enryakuji Shakadou Fort | Enryakuji Shakadou Fort | 延暦寺釈迦堂砦 | Mountaintop | No main keep but other buildings | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Fubukikaito Castle (Ina) | Fubukikaito Castle (Ina) | 小出フブキ外垣城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Fuchu Castle (Hitachi) | Fuchu Castle (Hitachi) | 常陸府中城 | Flatland | No main keep but other buildings | Edo Period | Ibaraki Prefecture | Viewer Contributed | 2022 | |
| Fudoudou Yakata | Fudoudou Yakata | 不動堂館 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Fujihashi Castle (Tokyo) | Fujihashi Castle (Tokyo) | 藤橋城 | Hilltop | Ruins only | Pre Edo Period | Tokyo | 2015 | 2015 | |
| Fujii Castle (Mikawa) | Fujii Castle (Mikawa) | 三河藤井城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2025 | |
| Fujikake Jin'ya | Fujikake Jin'ya | 藤懸陣屋 | Flatland | Ruins only | Edo Period | Kyoto | 2024 | 2024 | |
| Fujikawa Castle (Mikawa) | Fujikawa Castle (Mikawa) | 三河藤川城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Fujimaki Castle | Fujimaki Castle | 藤牧城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Fujimaki Yashiki | Fujimaki Yashiki | 藤巻屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Fujimaru Yakata | Fujimaru Yakata | 藤丸館 | Fortified Manor | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2024 | |
| Fujita Castle | Fujita Castle | 藤田城 | Hilltop | No main keep but other buildings | Pre Edo Period | Fukushima Prefecture | Viewer Contributed | 2017 | |
| Fukakusa Yakata | Fukakusa Yakata | 深草館 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2020 | |
| Fukayama Castle (Suruga) | Fukayama Castle (Suruga) | 駿河深山城 | Mountaintop | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2023 | |
| Fukazawa Castle | Fukazawa Castle | 深沢城 | Flatland | No main keep but other buildings | Pre Edo Period | Shizuoka Prefecture | 2014 | 2014 | |
| Fukigabora Castle | Fukigabora Castle | 吹ヶ洞城 | Mountaintop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2025 | |
| Fukouzu Castle | Fukouzu Castle | 深溝城 | Flatland | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Fukuchiyama Castle | Fukuchiyama Castle | 福知山城 | Hilltop | Reconstructed main keep | Edo Period | Kyoto | Viewer Contributed
2021 | 2009 | |
| Fukui Castle | Fukui Castle | 福井城 | Flatland | No main keep but other buildings | Edo Period | Fukui Prefecture | 2006
2023 | 2006 | |
| Fukui Castle (Shinano) | Fukui Castle (Shinano) | 信濃福井城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Fukujima Castle (Takai) | Fukujima Castle (Takai) | 高井福島城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Fukuju Fort (Odani Castle) | Fukuju Fort (Odani Castle) | 小谷城福寿砦 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2024 | |
| Fukuoka Castle | Fukuoka Castle | 福岡城 | Hilltop | No main keep but other buildings | Edo Period | Fukuoka Prefecture | Viewer Contributed | 2006 | |
| Fukuouji Yakata | Fukuoji Yakata | 福応寺館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Fukurouga Castle | Fukurouga Castle | 梟ヶ城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Fukushima Castle | Fukushima Castle | 福島城 | Flatland | Ruins only | Pre Edo Period | Fukushima Prefecture | Viewer Contributed | 2016 | |
| Fukushima Castle (Echigo) | Fukushima Castle (Echigo) | 越後福嶋城 | Flatland | Ruins only | Edo Period | Niigata Prefecture | Viewer Contributed | 2017 | |
| Fukushima Castle (Kiso) | Fukushima Castle (Kiso) | 木曽福島城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Fukutake Castle (Chikuzen) | Fukutake Castle (Chikuzen) | 筑前福嶽城 | Mountaintop | Ruins only | Pre Edo Period | Fukuoka Prefecture | Viewer Contributed | 2020 | |
| Fukuyama Castle | Fukuyama Castle | 福山城 | Hilltop | Reconstructed main keep | Edo Period | Hiroshima Prefecture | 2009
2023 | 2006 | |
| Fukuyo Castle | Fukuyo Castle | 福与城城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Fukuzawa Yakata | Fukuzawa Yakata | 福沢館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Fukuzuka Castle (Mino) | Mino Fukuzuka Castle | 美濃福束城 | Flatland | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2022 | |
| Fumimichi Castle | Fumimichi Castle | 文道城 | Mountaintop | Reconstructed main keep | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Funagatayama Castle | Funagatayama Castle | 船形山城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2025 | |
| Funage Castle | Funage Castle | 船上城 | Flatland | Ruins only | Pre Edo Period | Hyogo Prefecture | 2024 | 2024 | |
| Funai Castle | Funai Castle | 府内城 | Flatland | No main keep but other buildings | Edo Period | Oita Prefecture | Viewer Contributed | 2012 | |
| Funaki Castle (Omi) | Funaki Castle (Omi) | 近江船木城 | Flatland | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Funaoka Castle | Funaoka Castle | 船岡城 | Mountaintop | Ruins only | Pre Edo Period | Miyagi Prefecture | Viewer Contributed | 2017 | |
| Funaokayama Castle | Funaokayama Castle | 船岡山城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | Viewer Contributed | 2020 | |
| Funayama Castle | Funayama Castle | 船山城 | Mountaintop | Ruins only | Pre Edo Period | Hiroshima Prefecture | 2018 | 2019 | |
| Funayama Castle (Mikawa) | Funayama Castle (Mikawa) | 三河舟山城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Funehiki Castle | Funehiki Castle | 船引城 | Hilltop | Ruins only | Pre Edo Period | Fukushima Prefecture | Viewer Contributed | 2016 | |
| Furuhata Yakata | Furuhata Yakata | 古畑館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Furui Castle (Mikawa) | Furui Castle (Mikawa) | 三河古井城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Furujiro Fort | Furujiro Fort | 古城砦 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2025 | |
| Furujou Yakata | Furujou Yakata | 古城館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Furujouyama Castle (Hanishina) | Furujouyama Castle (Hanishina) | 埴科古城山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Furukawa Castle | Furukawa Castle | 古川城 | Hilltop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2022 | |
| Furumaya Castle (Azumi) | Furumaya Castle (Azumi) | 安曇古厩城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Furumaya Yakata | Furumaya Yakata | 安曇古厩館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Furumiya Castle | Furumiya Castle | 古宮城 | Hilltop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Furumiya Castle (Kai) | Furumiya Castle (Kai) | 甲斐古宮城 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Furusutobaru Ruins | Furusutobaru Ruins | フルスト原遺跡 | Hilltop | Ruins only | Pre Edo Period | Okinawa Prefecture | | 2024 | |
| Furuwatari Castle | Furuwatari Castle | 古渡城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2020 | |
| Fuse Castle (Sarashina) | Fuse Castle (Sarashina) | 更級布施城 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Fuseya Castle | Fuseya Castle | 伏屋城 | Flatland | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2024 | |
| Fuseyachouja Yakata | Fuseyachouja Yakata | 伏屋長者館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Fushimi Castle | Fushimi Castle | 伏見城 | Flatland | Reconstructed main keep | Pre Edo Period | Kyoto | 2022 | 2004 | |
| Fusou Castle (Mikawa) | Fusou Castle (Mikawa) | 三河不相城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Fusumada Castle | Fusumada Castle | 伏馬田城 | Mountaintop | Ruins only | Pre Edo Period | Kanagawa Prefecture | Viewer Contributed | 2023 | |
| Futae Castle (Azumi) | Futae Castle (Azumi) | 安曇二重城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Futamata Castle | Futamata Castle | 二俣城 | Mountaintop | Ruins only | Pre Edo Period | Shizuoka Prefecture | 2020 | 2010 | |
| Futatsu Bungonokami Yakata | Futatsu Bungonokami Yakata | 二木豊後守館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Futatsugi Castle (Azumi) | Futatsugi Castle (Azumi) | 安曇二木城 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Futoge Castle | Futoge Castle | 二曲城 | Mountaintop | Ruins only | Pre Edo Period | Ishikawa Prefecture | Viewer Contributed | 2017 | |
| Futoh'yama Castle | Futohyama Castle | 太尾山城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2020 | |
| Futsukamachi Castle | Futsukamachi Castle | 二日町城 | Mountaintop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2024 | |
| Futta Castle (Suwa) | Futta Castle (Suwa) | 諏訪古田城 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Fuwa no Seki | Fuwa no Seki | 不破関 | Flatland | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2024 | |
| Gakiyama Noroshidai | Gakiyama Noroshidai | 餓鬼山烽火台 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Gakuden Castle (Owari) | Gakuden Castle (Owari) | 尾張楽田城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2020 | |
| Ganjaku Castle | Ganjaku Castle | 岩石城 | Mountaintop | Reconstructed main keep | Pre Edo Period | Fukuoka Prefecture | Viewer Contributed | 2013 | |
| Ganryakuji Castle | Ganryakuji Castle | 岩略寺城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Ganshouin Yakata | Ganshouin Yakata | 岩松院館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Garyuzan Castle | Garyuzan Castle | 臥龍山城 | Mountaintop | No main keep but other buildings | Edo Period | Gifu Prefecture | Viewer Contributed | 2024 | |
| Gassan Toda Castle | Gassan Toda Castle | 月山富田城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Shimane Prefecture | 2010 | 2011 | |
| Genbao Castle | Genbao Castle | 玄蕃尾城 | Mountaintop | Ruins only | Pre Edo Period | Fukui Prefecture | 2023 | 2023 | |
| Genga Yashiki (Kai) | Genga Yashiki (Kai) | 甲斐玄賀屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Genji Yakata (Kai) | Genji Yakata (Kai) | 甲斐源氏館 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2021 | |
| Gentairi Castle | Gentairi Castle | 源太入城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Gifu Castle | Gifu Castle | 岐阜城 | Mountaintop | Reconstructed main keep | Pre Edo Period | Gifu Prefecture | 1992
1996
2019 | 1999 | |
| Gion Castle | Gion Castle | 祗園城 | Flatland | Ruins only | Pre Edo Period | Tochigi Prefecture | 2018 | 2018 | |
| Gobara Castle | Gobara Castle | 郷原城 | Mountaintop | Ruins only | Pre Edo Period | Gunma Prefecture | 2016 | 2016 | |
| Gochaku Castle | Gochaku Castle | 御着城 | Flatland | Ruins only | Pre Edo Period | Hyogo Prefecture | 2019 | 2020 | |
| Goi Castle (Mikawa) | Goi Castle (Mikawa) | 三河五井城 | Hilltop | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Gokan Castle | Gokan Castle | 後閑城 | Mountaintop | Ruins only | Pre Edo Period | Gunma Prefecture | 2015 | 2016 | |
| Goma Nakamura Castle | Goma Nakamura Castle | 胡麻中村城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2024 | 2025 | |
| Gongen Yakata | Gongen Yakata | 権現館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Gongen'yama Castle (Mino) | Gongen'yama Castle (Mino) | 美濃権現山城 | Mountaintop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2025 | |
| Goryokaku Fort | Goryokaku Fort | 五稜郭 | Flatland | No main keep but other buildings | Edo Period | Hokkaido | 2002 | 2002 | |
| Goryoudaira Fort | Goryoudaira Fort | 御領平塁 | Flatland | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Goryu Castle | Goryu Castle | 五龍城 | Mountaintop | Ruins only | Pre Edo Period | Hiroshima Prefecture | 2023 | 2023 | |
| Gouda Fort | Gouda Fort | 郷田砦 | Mountaintop | Ruins only | Pre Edo Period | Toyama Prefecture | Viewer Contributed | 2021 | |
| Goudo Castle | Goudo Castle | 顔戸城 | Flatland | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2025 | |
| Goudo Noroshidai | Goudo Noroshidai | 神戸烽火台 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2025 | |
| Gujo Hachiman Castle | Gujo Hachiman Castle | 郡上八幡城 | Mountaintop | Reconstructed main keep | Pre Edo Period | Gifu Prefecture | 2004 | 2004 | |
| Gushikawa Castle (Itoman Okinawa) | Gushikawa Castle (Itoman Okinawa) | 具志川城 | Flatland | Ruins only | Pre Edo Period | Okinawa Prefecture | Viewer Contributed | 2023 | |
| Gushikawa Castle (Kumejima Okinawa) | Gushikawa Castle (Kumejima Okinawa) | 具志川城 | Hilltop | Ruins only | Pre Edo Period | Okinawa Prefecture | | 2024 | |
| Ha Castle | Ha Castle | 羽城 | Flatland | No main keep but other buildings | Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Haba Castle | Haba Castle | 羽場城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Habako Castle | Habako Castle | 羽場古城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Habauehori Yashiki | Habauehori Yashiki | 巾上堀屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Habu Castle | Habu Castle | 埴生城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2023 | 2024 | |
| Hachigata Castle | Hachigata Castle | 鉢形城 | Hilltop | No main keep but other buildings | Pre Edo Period | Saitama Prefecture | 2006 | 2006 | |
| Hachikenchōja Castle | Hachikenchōja Castle | 八間長者城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Hachiman'yama Castle (Tanba) | Hachiman'yama Castle (Tanba) | 丹波八幡山城 | Mountaintop | Ruins only | Pre Edo Period | Hyogo Prefecture | Viewer Contributed | 2021 | |
| Hachimanpara Jinsho | Hachimanpara Jinsho | 八幡原陣所 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Hachimanshita Battery (Obama Domain) | Obama Domain Hachimanshita Battery | 小浜藩八幡下台場 | Flatland | Ruins only | Edo Period | Fukui Prefecture | Viewer Contributed | 2023 | |
| Hachinohe Castle | Hachinohe Castle | 八戸城 | Hilltop | No main keep but other buildings | Pre Edo Period | Aomori Prefecture | 2010 | 2010 | |
| Hachioji Castle | Hachioji Castle | 八王子城 | Mountaintop | Ruins only | Pre Edo Period | Tokyo | 2002
2013
2015 | 2002 | |
| Hadanashi Castle | Hadanashi Castle | 秦梨城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Hadanashiyama Castle | Hadanashiyama Castle | 秦梨山城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Haga Castle | Haga Castle | 波賀城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Hyogo Prefecture | Viewer Contributed | 2011 | |
| Hagi Castle | Hagi Castle | 萩城 | Flatland | No main keep but other buildings | Edo Period | Yamaguchi Prefecture | 2014
2024 | 2007 | |
| Hagikura Fort | Hagikura Fort | 萩倉砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Hagiwarasuwa Castle | Hagiwarasuwa Castle | 萩原諏訪城 | Flatland | Ruins only | Edo Period | Gifu Prefecture | Viewer Contributed | 2022 | |
| Haguro Castle (Owari) | Haguro Castle (Owari) | 尾張羽黒城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2020 | |
| Haibara Castle | Haibara Castle | 埴原城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | 2015 | 2016 | |
| Haiyama Castle | Haiyama Castle | 灰山城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2022 | 2022 | |
| Hajikamigou Castle | Hajikamigou Castle | 薑郷城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Hajoudo Castle | Hajoudo Castle | 半城土城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Hajoudoko Castle | Hajoudoko Castle | 半城土古城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Hakii Castle | Hakii Castle | 波木井城 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2025 | |
| Hakii Yakata | Hakii Yakata | 波木井館 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2025 | |
| Hakota Castle (Kozuke) | Hakota Castle (Kozuke) | 上野箱田城 | Mountaintop | Ruins only | Pre Edo Period | Gunma Prefecture | Viewer Contributed | 2021 | |
| Hakoyama Castle (Takai) | Hakoyama Castle (Takai) | 高井箱山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Hakoyanagi Castle | Hakoyanagi Castle | 箱柳城 | Hilltop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Hakusan Castle | Hakusan Castle | 白山城 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | 2015 | 2016 | |
| Hakusan Castle (Harima) | Hakusan Castle (Harima) | 播磨白山城 | Mountaintop | Ruins only | Pre Edo Period | Hyogo Prefecture | Viewer Contributed | 2017 | |
| Hamada Castle | Hamada Castle | 浜田城 | Mountaintop | No main keep but other buildings | Edo Period | Shimane Prefecture | 2014 | 2015 | |
| Hamada Castle (Ise) | Hamada Castle (Ise) | 伊勢浜田城 | Flatland | No main keep but other buildings | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2025 | |
| Hamagawa Castle | Hamagawa Castle | 浜川城 | Flatland | Ruins only | Pre Edo Period | Gunma Prefecture | Viewer Contributed | 2022 | |
| Hamamatsu Castle | Hamamatsu Castle | 浜松城 | Hilltop | Reconstructed main keep | Edo Period | Shizuoka Prefecture | 1999
2020 | 1999 | |
| Hanagoya Castle (Murakami Clan Fort Network) | Hanagoya Castle (Murakami Clan Fort Network) | 村上花古屋城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Hanakuma Castle | Hanakuma Castle | 花隈城 | Flatland | Ruins only | Pre Edo Period | Hyogo Prefecture | Viewer Contributed | 2016 | |
| Hanamaki Castle | Hanamaki Castle | 花巻城 | Hilltop | No main keep but other buildings | Pre Edo Period | Iwate Prefecture | Viewer Contributed | 2018 | |
| Hanaoka Castle (Azumi) | Hanaoka Castle (Azumi) | 安曇花岡城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Hanaoka Castle (Saku) | Hanaoka Castle (Saku) | 佐久花岡城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Hanaoka Castle (Suwa) | Hanaoka Castle (Suwa) | 諏訪花岡城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2019 | |
| Hanasaki Castle (Tsuru) | Hanasaki Castle (Tsuru) | 都留花咲城 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Hanawa Castle | Hanawa Castle | 花輪城 | Hilltop | Ruins only | Pre Edo Period | Chiba Prefecture | 2017 | 2017 | |
| Hanazawa Yakata | Hanazawa Yakata | 花沢館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Hanazono Castle | Hanazono Castle | 花園城 | Mountaintop | Ruins only | Pre Edo Period | Saitama Prefecture | 2018 | 2018 | |
| Hanazono Mitake Castle | Hanazono Mitake Castle | 花園御岳城 | Mountaintop | Ruins only | Pre Edo Period | Saitama Prefecture | 2018 | 2018 | |
| Hanehigashi Castle | Hanehigashi Castle | 羽根東城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Hanenishi Castle | Hanenishi Castle | 羽根西城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Haneo Castle | Haneo Castle | 羽根尾城 | Mountaintop | Ruins only | Pre Edo Period | Gunma Prefecture | Viewer Contributed | 2022 | |
| Hannyaji Castle | Hannyaji Castle | 般若寺城 | Mountaintop | Ruins only | Pre Edo Period | Hyogo Prefecture | 2024 | 2025 | |
| Harano Castle (Suwa) | Harano Castle (Suwa) | 原の城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Haranomoto Castle | Haranomoto Castle | 原ノ元城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Haruyamako Castle | Haruyamako Castle | 春山小城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Haruyamaoh Castle | Haruyamaoh Castle | 春山大城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Hasedo Castle | Hasedo Castle | 長谷堂城 | Mountaintop | Ruins only | Pre Edo Period | Yamagata Prefecture | 2017 | 2012 | |
| Hashira Castle (Mikawa) | Hashira Castle (Mikawa) | 三河柱城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Hatada Castle (Omi) | Hatada Castle (Omi) | 近江畑田城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2021 | |
| Hatakenaka Yakata | Hatakenaka Yakata | 畑中館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Hatayama Castle | Hatayama Castle | 波多山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Hatchou Castle (Mikawa) | Hatchou Castle (Mikawa) | 三河八丁城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Hatsuzawa Castle | Hatsuzawa Castle | 初沢城 | Mountaintop | Ruins only | Pre Edo Period | Tokyo | Viewer Contributed | 2020 | |
| Hatta Yashiki | Hatta Yashiki | 八田屋敷 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Hattori Castle (Koka) | Hattori Castle (Koka) | 服部城 | Hilltop | Ruins only | Pre Edo Period | Shiga Prefecture | 2022 | 2022 | |
| Hayakawa Yashiki (Kai) | Hayakawa Yashiki (Kai) | 甲斐早川屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Hayaotoshi Castle | Hayaotoshi Castle | 早落城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Hayashi Kohee Yashiki | Hayashi Kohee Yashiki | 林小兵衛屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Hayashikojo Castle | Hayashikojo Castle | 林小城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | 2015 | 2015 | |
| Hayashiohjo Castle | Hayashiohjo Castle | 林大城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | 2015 | 2015 | |
| Hayashizore Castle | Hayashizore Castle | 林添城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Hazu Castle (Ise) | Hazu Castle (Ise) | 伊勢羽津城 | Hilltop | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2025 | |
| Hazu Jin'ya | Hazu Jin'ya | 幡豆陣屋 | Flatland | Ruins only | Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Hekirichi Jinya | Hekirichi Jinya | 戸切地陣屋 | Flatland | No main keep but other buildings | Edo Period | Hokkaido | Viewer Contributed | 2011 | |
| Hekitani Castle | Hekitani Castle | 日置谷城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2024 | 2024 | |
| Henmi Yashiki (Kai) | Henmi Yashiki (Kai) | 甲斐逸見屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Hida Castle (Omi) | Hida Castle (Omi) | 近江肥田城 | Flatland | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Hieinoyama Fort | Hieinoyama Fort | 比叡ノ山砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Higashi Goma Castle | Higashi Goma Castle | 東胡麻城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2024 | 2025 | |
| Higashi Kuramae Castle | Higashi Kuramae Castle | 東蔵前城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Higashi Maruoka Castle (Koka) | Higashi Maruoka Castle (Koka) | 東丸岡城 | Hilltop | Ruins only | Pre Edo Period | Shiga Prefecture | 2022 | 2022 | |
| Higashi Sakabe Castle | Higashi Sakabe Castle | 東坂部城 | Hilltop | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2025 | |
| Higashi Wada Castle | Higashi Wada Castle | 東和田城 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Higashijou Castle (Chikuma) | Higashijou Castle (Chikuma) | 筑摩東条城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Higuchi Castle (Omi) | Higuchi Castle (Omi) | 近江樋口城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Higuchiuchi Castle (Ina) | Higuchiuchi Castle (Ina) | 伊那樋口内城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Hijika Castle | Hijika Castle | 日近城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Hijiyama Castle (Iga) | Iga Hijiyama Castle | 伊賀比自山城 | Mountaintop | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2022 | |
| Hikaru Castle | Hikaru Castle | 光城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Hiki Castle | Hiki Castle | 日岐城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Hikida Castle | Hikida Castle | 疋田城 | Mountaintop | Ruins only | Pre Edo Period | Fukui Prefecture | Viewer Contributed | 2023 | |
| Hikidono Yashiki | Hikidono Yashiki | 日岐殿屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Hikobe Yashiki | Hikobe Yashiki | 彦部屋敷 | Fortified Manor | No main keep but other buildings | Edo Period | Gunma Prefecture | 2020 | 2020 | |
| Hikone Castle | Hikone Castle | 彦根城 | Hilltop | Original main keep | Edo Period | Shiga Prefecture | 1996
2004
2019
2021
2022
2024 | 1999 | |
| Hikuma Castle | Hikuma Castle | 曳馬城 | Hilltop | Ruins only | Pre Edo Period | Shizuoka Prefecture | 2020 | 2020 | |
| Hime Castle (Chikuma) | Hime Castle (Chikuma) | 筑摩姫城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Hime Castle (Hanishina) | Hime Castle (Hanishina) | 村上姫城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Hime Castle (Mikawa) | Mikawa Hime Castle | 三河姫城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2020 | |
| Himega Castle (Mikawa) | Mikawa Himega Castle | 三河姫ヶ城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2022 | |
| Himeji Castle | Himeji Castle | 姫路城 | Hilltop | Original main keep | Edo Period | Hyogo Prefecture | 2009
1996
1997
1998
2004
2012
2018
2019
2022
2023
2024 | 1999 | |
| Himuro Yakata | Himuro Yakata | 氷室館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Hina Yashiki | Hina Yashiki | 日名屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Hinatabata Yakata | Hinatabata Yakata | 日向畑館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Hino Castle | Hino Castle | 日野城 | Hilltop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2023 | |
| Hinode Castle | Hinode Castle | 日ノ出城 | Hilltop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Hinohara Castle | Hinohara Castle | 檜原城 | Mountaintop | Ruins only | Pre Edo Period | Tokyo | Viewer Contributed | 2023 | |
| Hirabayashi Castle (Minochi) | Hirabayashi Castle (Minochi) | 水内平林城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Hirado Castle | Hirado Castle | 平戸城 | Hilltop | Reconstructed main keep | Edo Period | Nagasaki Prefecture | Viewer Contributed | 2011 | |
| Hirai Castle | Hirai Castle | 平井城 | Hilltop | Ruins only | Pre Edo Period | Gunma Prefecture | 2017 | 2017 | |
| Hirai Castle (Omi) | Hirai Castle (Omi) | 近江平居城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2021 | |
| Hirai Kanayama Castle | Hirai Kanayama Castle | 平井金山城 | Mountaintop | Ruins only | Pre Edo Period | Gunma Prefecture | 2017 | 2017 | |
| Hirai Yashiki (Kai) | Hirai Yashiki (Kai) | 甲斐平井屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Hiraide Moated Settlement | Hiraide Moated Settlement | 平出環濠集落 | Flatland | No main keep but other buildings | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Hiraiwa Castle (Mikawa) | Hiraiwa Castle (Mikawa) | 三河平岩城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Hiraizumi Date | Hiraizumi Date | 平泉館 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Iwate Prefecture | Viewer Contributed | 2023 | |
| Hirakura Castle | Hirakura Castle | 平倉城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Hirao Castle (Ise) | Hirao Castle (Ise) | 伊勢平尾城 | Hilltop | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2025 | |
| Hirase Castle | Hirase Castle | 平瀬城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Hirase Kitano Castle | Hirase Kitano Castle | 平瀬北ノ城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Hirase Noroshidai | Hirase Noroshidai | 平瀬烽火台 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Hirase Yakata | Hirase Yakata | 平瀬館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Hirata Yashiki | Hirata Yashiki | 平田屋敷 | Fortified Manor | No main keep but other buildings | Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Hiratsuka Castle | Hiratsuka Castle | 平塚城 | Hilltop | Ruins only | Pre Edo Period | Tokyo | 2021 | 2021 | |
| Hirosaki Castle | Hirosaki Castle | 弘前城 | Hilltop | Original main keep | Edo Period | Aomori Prefecture | 1999
2010 | 1999 | |
| Hirose Castle (Hida) | Hida Hirose Castle | 飛騨広瀬城 | Mountaintop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2022 | |
| Hiroshima Castle | Hiroshima Castle | 広島城 | Flatland | Reconstructed main keep | Edo Period | Hiroshima Prefecture | 1996
2014
2018 | 1999 | |
| Hirota Castle | Hirota Castle | 広田城 | Flatland | No main keep but other buildings | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Hisawa Castle | Hisawa Castle | 干沢城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Hishakuyama Castle | Hishakuyama Castle | 柄杓山城 | Mountaintop | Ruins only | Pre Edo Period | Gunma Prefecture | 2020 | 2020 | |
| Hitomoshi Castle (Saku) | Hitomoshi Castle (Saku) | 佐久火燈城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Hitomoshiyama Fort (Suwa) | Hitomoshiyama Fort (Suwa) | 諏訪火燈山砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Hitoyoshi Castle | Hitoyoshi Castle | 人吉城 | Hilltop | No main keep but other buildings | Edo Period | Kumamoto Prefecture | Viewer Contributed | 2012 | |
| Hiyama Castle | Hiyama Castle | 檜山城 | Mountaintop | Ruins only | Pre Edo Period | Akita Prefecture | 2020 | 2021 | |
| Hizen Nagoya Castle | Hizen Nagoya Castle | 肥前名護屋城 | Hilltop | Ruins only | Pre Edo Period | Saga Prefecture | Viewer Contributed | 2011 | |
| Hobonishi Castle | Hobonishi Castle | 保々西城 | Hilltop | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2025 | |
| Hodarakuji Castle | Hodarakuji Castle | 補陀楽寺城 | Flatland | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2019 | |
| Hojo Clan Residence | Hojo Clan Residence | 円成寺北条氏邸 | Fortified Manor | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2021 | |
| Hokkyu Castle | Hokkyu Castle | 保久城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Hokkyu Jin'ya | Hokkyu Jin'ya | 保久陣屋 | Hilltop | Ruins only | Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Hongou Castle (Owari) | Hongou Castle (Owari) | 尾張本郷城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2025 | |
| Honjin'yama Castle (Mino) | Honjin'yama Castle (Mino) | 美濃本陣山城・美濃御嵩城 | Mountaintop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2025 | |
| Honjinzawabata Fort | Honjinzawabata Fort | 本神沢端砦 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Honshouji Castle | Honshouji Castle | 本證寺城 | Flatland | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2020 | |
| Hora Castle (Mikawa) | Hora Castle (Mikawa) | 三河洞城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Hora Yakata | Hora Yakata | 洞館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Hori Castle (Minochi) | Hori Castle (Minochi) | 水内穂里城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Horigane Yakata | Horigane Yakata | 堀金館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Horigoe Palace | Horigoe Palace | 堀越御所 | Flatland | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2021 | |
| Horikawa Castle | Horikawa Castle | 堀川城 | Flatland | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2024 | |
| Horikoshi Castle | Horikoshi Castle | 堀越城 | Flatland | Ruins only | Pre Edo Period | Aomori Prefecture | 2020 | 2021 | |
| Horinouchi Castle (Kai) | Horinouchi Castle (Kai) | 甲斐堀之内城 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Horinouchi Yakata (Azumi) | Horinouchi Yakata (Azumi) | 安曇堀之内館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Horinouchi Yakata (Ina) | Horinouchi Yakata (Ina) | 伊那堀ノ内館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Horinouchi Yashiki | Horinouchi Yashiki | 堀内屋敷 | Fortified Manor | No main keep but other buildings | Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Horishi Yakata (Omi) | Horishi Yakata (Omi) | 近江堀氏館 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2025 | |
| Horiuchi Castle (Mikawa) | Horiuchi Castle (Mikawa) | 三河堀内城 | Fortified Manor | Ruins only | Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Horiuchi Shingu Castle | Horiuchi Shingu Castle | 堀内新宮城 | Fortified Manor | Ruins only | Pre Edo Period | Wakayama Prefecture | Viewer Contributed | 2025 | |
| Hoshigasaki Castle | Hoshigasaki Castle | 星ヶ崎城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | 2022 | 2022 | |
| Hoshina Maenoyama Fort | Hoshina Maenoyama Fort | 保科前の山砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Hoshina Yakata | Hoshina Yakata | 保科館 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Hoshiyamako Castle | Hoshiyamako Castle | 星山古城 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2025 | |
| Hosogaya Yakata | Hosogaya Yakata | 細萱館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Hosokawagonsui Castle | Hosokawagonsui Castle | 細川権水城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Hosokawaonmaeda Castle | Hosokawaonmaeda Castle | 細川御前田城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Hosokawashiroyama Castle | Hosokawashiroyama Castle | 細川城山城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Hosshouji Castle (Mikawa) | Hosshouji Castle (Mikawa) | 三河法性寺城 | Fortified Manor | Ruins only | Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Hotaka Yakata | Hotaka Yakata | 穂高館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Hotta no Saku | Hotta no Saku | 払田柵 | Flatland | No main keep but other buildings | Pre Edo Period | Akita Prefecture | Viewer Contributed | 2012 | |
| Houjiin Doi | Houjiin Doi | 宝持院土居 | Fortified Manor | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2022 | |
| Hourinji Yakata | Hourinji Yakata | 法林寺館 | Fortified Manor | Ruins only | Pre Edo Period | Tokyo | Viewer Contributed | 2023 | |
| Houshouji Fort | Houshouji Fort | 宝生寺砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Houzouji Yakata | Houzouji Yakata | 法蔵寺館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Hyakusaiji Castle | Hyakusaiji Castle | 百済寺城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2013 | |
| Hyogo Castle | Hyogo Castle | 兵庫城 | Flatland | No main keep but other buildings | Edo Period | Hyogo Prefecture | Viewer Contributed | 2020 | |
| Iba Castle | Iba Castle | 伊庭城 | Flatland | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Iba Palace | Iba Palace | 伊庭御殿 | Flatland | Ruins only | Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Ibako Castle | Ibako Castle | 伊庭古城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Ibaraki Castle | Ibaraki Castle | 茨木城 | Flatland | No main keep but other buildings | Pre Edo Period | Osaka | 2014 | 2014 | |
| Ibarayama Castle | Ibarayama Castle | 茨山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Ibayama Castle | Ibayama Castle | 伊庭山城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Ibi Castle | Ibi Castle | 揖斐城 | Mountaintop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2025 | |
| Ibuka Castle | Ibuka Castle | 伊深城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Ichiba Castle (Ise) | Ichiba Castle (Ise) | 伊勢市場城 | Hilltop | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2025 | |
| Ichibajin'yama Castle (Koka) | Kouka Ichibajin'yama Castle | 甲賀市場陣山城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2021 | |
| Ichigousan Castle | Ichigousan Castle | 一郷山城 | Mountaintop | Reconstructed main keep | Pre Edo Period | Gunma Prefecture | Viewer Contributed | 2022 | |
| Ichijodani Castle | Ichijodani Castle | 一乗谷城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Fukui Prefecture | 2023 | 2013 | |
| Ichijodani Kojo Castle | Ichijodani Kojo Castle | 小城 | Mountaintop | Ruins only | Pre Edo Period | Fukui Prefecture | 2023 | 2023 | |
| Ichijodaniyama Castle | Ichijodaniyama Castle | 一乗谷山城 | Mountaintop | Ruins only | Pre Edo Period | Fukui Prefecture | 2023 | 2023 | |
| Ichijojiyama Castle | Ichijojiyama Castle | 一乗寺山城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2021 | 2022 | |
| Ichikawa Jin'ya | Ichikawa Jin'ya | 市川陣屋 | Flatland | Ruins only | Edo Period | Yamanashi Prefecture | Viewer Contributed | 2021 | |
| Ichinodaira Castle (Ina) | Ichinodaira Castle (Ina) | 伊那一ノ平城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Ichinomiya Castle | Ichinomiya Castle | 一宮城 | Mountaintop | Ruins only | Pre Edo Period | Tokushima Prefecture | Viewer Contributed | 2012 | |
| Ida Castle (Mikawa) | Ida Castle (Mikawa) | 三河井田城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Ide Yakata | Ide Yakata | 井出館 | Fortified Manor | No main keep but other buildings | Edo Period | Shizuoka Prefecture | Viewer Contributed | 2023 | |
| Iden Castle | Iden Castle | 位田城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2024 | 2025 | |
| Iden Miyanokoshi Castle | Iden Miyanokoshi Castle | 位田宮越城 | Fortified Manor | Ruins only | Pre Edo Period | Kyoto | 2024 | 2025 | |
| Iga Castle (Mikawa) | Iga Castle (Mikawa) | 三河伊賀城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Iga Ueno Castle | Iga Ueno Castle | 伊賀上野城 | Hilltop | Reconstructed main keep | Edo Period | Mie Prefecture | 2012 | 2007 | |
| Igawa Castle | Igawa Castle | 井川城 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Ii Yakata | Ii Yakata | 井伊館 | Fortified Manor | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2024 | |
| Iida Castle | Iida Castle | 飯田城 | Hilltop | No main keep but other buildings | Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Iida Castle (Azumi) | Iida Castle (Azumi) | 安曇飯田城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Iida Castle (Totomi) | Iida Castle (Totomi) | 遠江飯田城 | Mountaintop | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2025 | |
| Iida Fort | Iida Fort | 飯田砦 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Iida Yashiki | Iida Yashiki | 飯田屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Iidako Castle (Totomi) | Iidako Castle (Totomi) | 遠江飯田古城 | Mountaintop | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2025 | |
| Iijima Jin'ya | Iijima Jin'ya | 飯島陣屋 | Flatland | No main keep but other buildings | Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Iimori Castle | Iimori Castle | 飯盛城 | Mountaintop | Ruins only | Pre Edo Period | Osaka | 2023 | 2023 | |
| Iimori Castle (Azumi) | Iimori Castle (Azumi) | 安曇飯森城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Iimoriyama Castle (Asuke) | Iimoriyama Castle (Asuke) | 足助飯盛山城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Iinawa Castle | Iinawa Castle | 飯縄城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Iino Taira Castle | Iino Taira Castle | 飯野平城・大館城 | Hilltop | Ruins only | Pre Edo Period | Fukushima Prefecture | Viewer Contributed | 2018 | |
| Iinoya Castle | Iinoya Castle | 井伊谷城 | Mountaintop | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2024 | |
| Iinuma Castle | Iinuma Castle | 飯沼城 | Flatland | Ruins only | Pre Edo Period | Ibaraki Prefecture | Viewer Contributed | 2018 | |
| Iiyama Castle | Iiyama Castle | 飯山城 | Hilltop | No main keep but other buildings | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Iizuna Castle (Murakami Clan Fort Network) | Iizuna Castle (Murakami Clan Fort Network) | 村上飯綱城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Iji Castle | Iji Castle | 伊治城 | Flatland | No main keep but other buildings | Pre Edo Period | Miyagi Prefecture | Viewer Contributed | 2023 | |
| Ijiri Yashiki | Ijiri Yashiki | 井尻屋敷 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Ikarashi Yakata | Ikarashi Yakata | 五十嵐館 | Fortified Manor | Ruins only | Pre Edo Period | Niigata Prefecture | Viewer Contributed | 2023 | |
| Ikeda Castle | Ikeda Castle | 池田城 | Hilltop | Reconstructed main keep | Pre Edo Period | Osaka | 2013 | 2012 | |
| Ikeda Castle (Mino) | Ikeda Castle (Mino) | 美濃池田城 | Mountaintop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2021 | |
| Ikeda Yakata (Omi) | Ikeda Yakata (Omi) | 近江池田館 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Ikenoshiri Yakata | Ikenoshiri Yakata | 池尻館 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2021 | |
| Ikkui Yashiki (Kai) | Ikkui Yashiki (Kai) | 甲斐飯喰屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Ima Castle (Mino) | Ima Castle (Mino) | 美濃今城 | Mountaintop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2021 | |
| Imabari Castle | Imabari Castle | 今治城 | Flatland | Reconstructed main keep | Edo Period | Ehime Prefecture | 2001 | 2001 | |
| Imai Castle | Imai Castle | 今井城 | Hilltop | Ruins only | Pre Edo Period | Tokyo | 2015 | 2015 | |
| Imai Fort | Imai Fort | 今井砦 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Imai Jin'ya | Imai Jin'ya | 今井陣屋 | Flatland | Ruins only | Edo Period | Nagano Prefecture | Viewer Contributed | 2019 | |
| Imai Yashiki (Kai) | Imai Yashiki (Kai) | 甲斐今井屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Imamura Castle (Omi) | Imamura Castle (Omi) | 近江今村城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Imamura Castle (Yamashiro) | Imamura Castle (Yamashiro) | 山城今村城 | Fortified Manor | Ruins only | Pre Edo Period | Kyoto | Viewer Contributed | 2020 | |
| Imasu Castle (Mino) | Imasu Castle (Mino) | 美濃今須城 | Flatland | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2025 | |
| Imori Castle (Suwa) | Imori Castle (Suwa) | 諏訪井森城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Imoto Castle (Omi) | Imoto Castle (Omi) | 近江井本城 | Hilltop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2021 | |
| Ina Castle | Ina Castle | 伊奈城 | Flatland | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2020 | |
| Ina Yashiki | Ina Yashiki | 伊奈氏屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Saitama Prefecture | 2022 | 2022 | |
| Inamura Castle (Ina) | Inamura Castle (Ina) | 伊那稲村城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Inamurafuru Castle | Inamurafuru Castle | 稲村古城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Inaniwa Castle | Inaniwa Castle | 稲庭城 | Mountaintop | Reconstructed main keep | Pre Edo Period | Akita Prefecture | Viewer Contributed | 2016 | |
| Inariyama Castle (Saku) | Inariyama Castle (Saku) | 佐久稲荷山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Inariyama Castle (Sarashina) | Inariyama Castle (Sarashina) | 更級稲荷山城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Inatsuke Castle | Inatsuke Castle | 稲付城 | Hilltop | Ruins only | Pre Edo Period | Tokyo | 2015 | 2015 | |
| Inawashiro Castle | Inawashiro Castle | 猪苗代城 | Hilltop | Ruins only | Edo Period | Fukushima Prefecture | 2011 | 2011 | |
| Injiki Castle | Injiki Castle | 印食城 | Flatland | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2024 | |
| Innoshima Suigun Castle | Innoshima Suigun Castle | 因島水軍城 | Hilltop | Reconstructed main keep | Pre Edo Period | Hiroshima Prefecture | Viewer Contributed | 2013 | |
| Inoko Yakata | Inoko Yakata | 猪子館 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Inokuchi Castle | Inokuchi Castle | 井ノ口城 | Hilltop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Inokuchi Castle (Nukata) | Inokuchi Castle (Nukata) | 額田井口城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Inokura Castle | Inokura Castle | 猪倉城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2023 | 2024 | |
| Inoue Castle | Inoue Castle | 井上城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Inoue Yakata | Inoue Yakata | 井上館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Inoue Yakata (Shiga) | Inoue Yakata (Shiga) | 井上氏館 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | 2022 | 2023 | |
| Inuinofuru Castle | Inuinofuru Castle | 乾ノ古城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Inukai Castle | Inukai Castle | 犬甘城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | 2015 | 2016 | |
| Inukai Yakata | Inukai Yakata | 犬甘館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Inuyama Castle | Inuyama Castle | 犬山城 | Hilltop | Original main keep | Edo Period | Aichi Prefecture | 1992
1996
2004 | 1999 | |
| Ioto Castle | Ioto Castle | 五百渡城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Iouji Fort | Iouji Fort | 医王寺砦 | Mountaintop | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Ioyama Castle | Ioyama Castle | 医王山城 | Mountaintop | Ruins only | Pre Edo Period | Okayama Prefecture | Viewer Contributed | 2013 | |
| Iroganeyama Fort | Iroganeyama Fort | 色金山砦 | Mountaintop | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Isawa Castle | Isawa Castle | 胆沢城 | Flatland | Ruins only | Pre Edo Period | Iwate Prefecture | Viewer Contributed | 2018 | |
| Isawa Jin'ya | Isawa Jin'ya | 石和陣屋 | Flatland | No main keep but other buildings | Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Isezaki Castle (Sanada) | Isezaki Castle (Sanada) | 真田伊勢崎城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Ishibashi Castle | Ishibashi Castle | 石橋城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Ishibayama Castle (Omi) | Ishibayama Castle | 石馬山城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Ishida Castle (Mikawa) | Ishida Castle (Mikawa) | 三河石田城 | Hilltop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Ishida Jin'ya | Ishida Jin'ya | 石田陣屋 | Flatland | Ruins only | Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Ishigakiyama Ichiya Castle | Ishigakiyama Ichiya Castle | 石垣山一夜城 | Mountaintop | Ruins only | Pre Edo Period | Kanagawa Prefecture | 2009 | 2009 | |
| Ishigami Castle | Ishigami Castle | 石神城 | Hilltop | Ruins only | Pre Edo Period | Ibaraki Prefecture | Viewer Contributed | 2018 | |
| Ishihama Castle | Ishihama Castle | 石浜城 | Flatland | Ruins only | Pre Edo Period | Tokyo | Viewer Contributed
2020 | 2022 | |
| Ishikawa Jouzan Yashiki | Ishikawa Jouzan Yashiki | 石川丈山屋敷 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Ishimakiyama Castle | Ishimakiyama Castle | 石巻山城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2025 | |
| Ishimura Castle | Ishimura Castle | 石村城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Ishinomaki Castle | Ishinomaki Castle | 石巻城跡 | Hilltop | Ruins only | Pre Edo Period | Miyagi Prefecture | Viewer Contributed | 2023 | |
| Ishitono Yashiki | Ishitono Yashiki | 石殿屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Ishiwata Yakata | Ishiwata Yakata | 石渡館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Isobe Castle | Isobe Castle | 磯部城 | Mountaintop | Ruins only | Pre Edo Period | Gunma Prefecture | 2018 | 2018 | |
| Isobe Castle (Mikawa) | Isobe Castle (Mikawa) | 三河磯辺城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Isshiki Castle (Chita) | Isshiki Castle (Chita) | 知多一色城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Isshiki Castle (Omi) | Isshiki Castle | 一式城 | Flatland | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2021 | |
| Isshiki Castle (Suruga) | Isshiki Castle (Suruga) | 駿河一色城 | Hilltop | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2023 | |
| Isshindenjinai Moated Settlement | Isshindenjinai Moated Settlement | 一身田寺内環濠集落 | Flatland | No main keep but other buildings | Edo Period | Mie Prefecture | Viewer Contributed | 2025 | |
| Itabashi Castle | Itabashi Castle | 板橋城 | Hilltop | Ruins only | Pre Edo Period | Tokyo | 2021 | 2022 | |
| Itadafuru Yashiki (Mikawa) | Itadafuru Yashiki (Mikawa) | 三河板田古屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Itagaki Kanenobu Yashiki | Itagaki Kanenobu Yashiki | 板垣兼信屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Itagakiyama Noroshidai | Itagakiyama Noroshidai | 板垣山烽火台 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Itami Castle | Itami Castle | 伊丹城 | Flatland | Ruins only | Pre Edo Period | Hyogo Prefecture | 2013 | 2013 | |
| Itazuke Moated Settlement | Itazuke Moated Settlement | 板付環濠集落 | Flatland | No main keep but other buildings | Pre Edo Period | Fukuoka Prefecture | Viewer Contributed | 2020 | |
| Itoi Jin'ya | Itoi Jin'ya | 糸井陣屋 | Flatland | No main keep but other buildings | Edo Period | Hyogo Prefecture | Viewer Contributed | 2021 | |
| Itoigawa Jinya | Itoigawa Jinya | 糸魚川陣屋 | Hilltop | Ruins only | Edo Period | Niigata Prefecture | Viewer Contributed | 2021 | |
| Itokazu Castle | Itokazu Castle | 糸数城 | Hilltop | Ruins only | Pre Edo Period | Okinawa Prefecture | | 2022 | |
| Itou Genba Yashiki | Itou Genba Yashiki | 伊藤玄蕃屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Itousakaue Fort | Itousakaue Fort | 伊藤坂上砦 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Iuchi Castle (Mikawa) | Iuchi Castle (Mikawa) | 三河井内城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Iwabitsu Castle | Iwabitsu Castle | 岩櫃城 | Mountaintop | Ruins only | Pre Edo Period | Gunma Prefecture | 2016 | 2016 | |
| Iwabuchi Castle (Aida) | Iwabuchi Castle (Aida) | 会田岩渕城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Iwade Danjou Kyokan | Iwade Danjou Kyokan | 岩手弾正居館 | Fortified Manor | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2020 | |
| Iwade Yashiki (Kai) | Iwade Yashiki (Kai) | 甲斐岩手屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Iwadono Castle | Iwadono Castle | 岩殿城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Yamanashi Prefecture | 2019 | 2011 | |
| Iwahara Castle (Azumi) | Iwahara Castle (Azumi) | 安曇岩原城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Iwahori Castle (Mikawa) | Iwahori Castle (Mikawa) | 三河岩堀城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Iwaki Taira Castle | Iwaki Taira Castle | 磐城平城 | Hilltop | No main keep but other buildings | Edo Period | Fukushima Prefecture | Viewer Contributed | 2015 | |
| Iwakiri Castle | Iwakiri Castle | 岩切城 | Mountaintop | Ruins only | Pre Edo Period | Miyagi Prefecture | 2020 | 2021 | |
| Iwakubo Yakata | Iwakubo Yakata | 岩窪館 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Iwakuni Castle | Iwakuni Castle | 岩国城 | Mountaintop | Reconstructed main keep | Edo Period | Yamaguchi Prefecture | 1996
1998
2019 | 1999 | |
| Iwakura Castle | Iwakura Castle | 岩倉城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Iwakura Castle (Mikawa) | Iwakura Castle (Mikawa) | 三河岩倉城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Iwakura Castle (Owari) | Iwakura Castle (Owari) | 尾張岩倉城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Iwakura Yakata (Mikawa) | Iwakura Yakata (Mikawa) | 三河岩倉館 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Iwakuratouge Castle (Mikawa) | Iwakuratouge Castle (Mikawa) | 岩倉峠城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Iwamura Castle | Iwamura Castle | 岩村城 | Mountaintop | No main keep but other buildings | Edo Period | Gifu Prefecture | 2014 | 2007 | |
| Iwaoka Yakata | Iwaoka Yakata | 岩岡館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Iwasaki Castle | Iwasaki Castle | 岩崎城 | Hilltop | Reconstructed main keep | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2008 | |
| Iwasaki Castle (Hanishina) | Iwasaki Castle (Hanishina) | 村上岩崎城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Iwasaki Castle (Mutsu) | Iwasaki Castle (Mutsu) | 陸奥岩崎城 | Hilltop | Ruins only | Pre Edo Period | Iwate Prefecture | Viewer Contributed | 2018 | |
| Iwasaki Yakata | Iwasaki Yakata | 岩崎館 | Hilltop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Iwasakiyama Fort | Iwasakiyama Fort | 岩崎山砦 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | 2024 | 2025 | |
| Iwaseyama Castle | Iwaseyama Castle | 岩瀬山城 | Mountaintop | Ruins only | Pre Edo Period | Fukushima Prefecture | Viewer Contributed | 2017 | |
| Iwato Castle (Mikawa) | Iwato Castle (Mikawa) | 三河岩戸城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Iwatsuki Castle | Iwatsuki Castle | 岩槻城 | Flatland | No main keep but other buildings | Edo Period | Saitama Prefecture | 2009 | 2009 | |
| Iwaya Castle | Iwaya Castle | 岩屋城 | Mountaintop | Ruins only | Pre Edo Period | Fukuoka Prefecture | Viewer Contributed | 2013 | |
| Iwazu Castle | Iwazu Castle | 岩津城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Iwazu Daizen Castle | Iwazu Daizen Castle | 岩津大膳城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Iwazu Daizennishi Castle | Iwazu Daizennishi Castle | 岩津大膳西城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Iwazu Dannoue Castle | Iwazu Dannoue Castle | 岩津壇ノ上城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Iwazu Ino Castle | Iwazu Ino Castle | 岩津井ノ城 | Hilltop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Iwazu Kibira Castle | Iwazu Kibira Castle | 岩津木平城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Iwazu Myoshinji Castle | Iwazu Myoshinji Castle | 岩津妙心寺城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Iwazu Naruse Castle | Iwazu Naruse Castle | 岩津成瀬城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Iwazushin Castle | Iwazushin Castle | 岩津新城 | Hilltop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Iyo Matsuyama Castle | Iyo Matsuyama Castle | 伊予松山城 | Hilltop | Original main keep | Edo Period | Ehime Prefecture | 2001
2016 | 2001 | |
| Izaki Castle | Izaki Castle | 猪崎城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2021 | 2022 | |
| Izu Nagahama Castle | Izu Nagahama Castle | 伊豆長浜城 | Hilltop | No main keep but other buildings | Pre Edo Period | Shizuoka Prefecture | 2016 | 2016 | |
| Izuki Jin'ya | Izuki Jin'ya | 伊豆木陣屋 | Hilltop | No main keep but other buildings | Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Izumi Jin'ya | Izumi Jin'ya | 泉陣屋 | Flatland | No main keep but other buildings | Edo Period | Fukushima Prefecture | Viewer Contributed | 2016 | |
| Izumigashira Castle | Izumigashira Castle | 泉頭城 | Flatland | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2021 | |
| Izushi Castle | Izushi Castle | 出石城 | Hilltop | No main keep but other buildings | Edo Period | Hyogo Prefecture | 2013 | 2004 | |
| Jikki Yashiki | Jikki Yashiki | 十騎屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Jikouin Fort | Jikouin Fort | 慈光院砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Jikouin Yakata | Jikouin Yakata | 慈光院館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Jinbagahara Castle | Jinbagahara Castle | 陣場ヶ原城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Jindaiji Castle | Jindaiji Castle | 深大寺城 | Hilltop | Ruins only | Pre Edo Period | Tokyo | 2015 | 2012 | |
| Jinguuji Yakata | Jinguuji Yakata | 神宮寺館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Jinnoya Castle (Mikawa) | Jinnoya Castle (Mikawa) | 三河陣ノ屋城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Jionji Yakata | Jionji Yakata | 慈恩寺館 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Jissouji Yakata | Jissouji Yakata | 実相寺館 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2025 | |
| Jizen Castle (Koka) | Jizen Castle (Koka) | 寺前城 | Hilltop | Ruins only | Pre Edo Period | Shiga Prefecture | 2022 | 2022 | |
| Jofukuji Castle | Jofukuji Castle | 浄福寺城 | Mountaintop | Ruins only | Pre Edo Period | Tokyo | 2016 | 2016 | |
| Jou Ian Yashiki | Jou Ian Yashiki | 城伊庵屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Jouguuji Castle | Jouguuji Castle | 上宮寺城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Jouhikage Fort | Jouhikage Fort | 城日影砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Joujou Castle | Joujou Castle | 上条城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2020 | |
| Joukouin Yakata | Joukouin Yakata | 城光院館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Joumineyama Castle | Joumineyama Castle | 城峰山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Joumura Castle (Ina) | Joumura Castle (Ina) | 伊那城村城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Joumurafuru Castle | Joumurafuru Castle | 城村古城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Jounoue Fort | Jounoue Fort | 城ノ上砦 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Jukkumi Yashiki | Jukkumi Yashiki | 十組屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Junhanshi Yashiki | Junhashi Yashiki | 准藩士屋敷 | Fortified Manor | Ruins only | Edo Period | Fukui Prefecture | Viewer Contributed | 2023 | |
| Jurakudai | Jurakudai | 聚楽第 | Flatland | No main keep but other buildings | Pre Edo Period | Kyoto | Viewer Contributed | 2020 | |
| Juuouzan Fort | Juuouzan Fort | 十王山砦 | Mountaintop | Ruins only | Pre Edo Period | Gunma Prefecture | Viewer Contributed | 2022 | |
| Kabuto Castle | Kabuto Castle | 鹿伏兎城 | Mountaintop | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2025 | |
| Kadone Castle (Omi) | Kadone Castle (Omi) | 近江門根城 | Hilltop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kaesa Castle | Kaesa Castle | 替佐城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kagami Yakata | Kagami Yakata | 加賀美館 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Kagamiyama Fort | Kagamiyama Fort | 鏡山砦 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Kaganoi Castle | Kaganoi Castle | 加賀野井城 | Flatland | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2024 | |
| Kageyama Castle (Mikawa) | Kageyama Castle (Mikawa) | 三河影山城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kagikakemonomi Fort | Kagikakemonomi Fort | 鍵掛物見砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Kagohana Fort | Kagohana Fort | 籠鼻砦 | Mountaintop | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2025 | |
| Kagoshima Castle | Kagoshima Castle | 鹿児島城 | Flatland | No main keep but other buildings | Edo Period | Kagoshima Prefecture | Viewer Contributed | 2013 | |
| Kaguraoka Castle | Kaguraoka Castle | 神楽岡城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2024 | 2024 | |
| Kaibai Castle | Kaibai Castle | 貝梅城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kaibara Jinya | Kaibara Jinya | 柏原陣屋 | Flatland | No main keep but other buildings | Edo Period | Hyogo Prefecture | Viewer Contributed | 2020 | |
| Kaiden Castle | Kaiden Castle | 開田城 | Fortified Manor | Ruins only | Pre Edo Period | Kyoto | 2014 | 2014 | |
| Kaize Castle (Saku) | Kaize Castle (Saku) | 佐久海瀬城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kajiya Castle | Kajiya Castle | 鍛冶屋城 | Hilltop | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kake Castle (Hazu) | Kake Castle (Hazu) | 幡豆欠城 | Hilltop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kake Castle (Nukata) | Kake Castle (Nukata) | 額田欠城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kakegawa Castle | Kakegawa Castle | 掛川城 | Hilltop | Reconstructed main keep | Edo Period | Shizuoka Prefecture | 1999
2009 | 1999 | |
| Kakegawako Castle | Kakegawako Castle | 掛川古城 | Mountaintop | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2022 | |
| Kakiage Castle (Chikuma) | Kakiage Castle (Chikuma) | 筑摩掻揚城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Kakimi Castle (Omi) | Kakimi Castle (Omi) | 近江垣見城 | Flatland | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kakinohana Castle | Kakinohana Castle | 垣花城 | Hilltop | Ruins only | Pre Edo Period | Okinawa Prefecture | Viewer Contributed | 2023 | |
| Kakizaki Castle | Kakizaki Castle | 柿崎城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Niigata Prefecture | Viewer Contributed | 2023 | |
| Kakuhari Yashiki | Kakuhari Yashiki | 角張屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Kakunodate Castle | Kakunodate Castle | 角館城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Akita Prefecture | 1998
2004
2018 | 1999 | |
| Kakutsugawa Castle | Kakutsugawa Castle | 鹿勝川城 | Hilltop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kamaenohaka Yakata | Kamaenohaka Yakata | 構え之墓館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kamagari Castle (Omi) | Kamagari Castle (Omi) | 近江河曲城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kamagatake Castle | Kamagatake Castle | 鎌ヶ嶽城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kamaha Castle | Kamaha Castle | 鎌刃城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | 2022 | 2023 | |
| Kamaian Yakata | Kamaian Yakata | 釜井庵館 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kamakata Jin'ya | Kamakata Jin'ya | 蒲形陣屋 | Flatland | No main keep but other buildings | Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kameda Castle | Kameda Castle | 亀田城 | Flatland | Reconstructed main keep | Edo Period | Akita Prefecture | Viewer Contributed | 2016 | |
| Kamegasaki Castle | Kamegasaki Castle | 亀ヶ崎城 | Flatland | No main keep but other buildings | Edo Period | Yamagata Prefecture | Viewer Contributed | 2023 | |
| Kamei Castle | Kamei Castle | 亀居城 | Hilltop | Ruins only | Edo Period | Hiroshima Prefecture | 2018 | 2012 | |
| Kamei Castle (Murakami Clan Fort Network) | Kamei Castle (Murakami Clan Fort Network) | 村上亀井城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kameyama Battery | Kameyama Battery | 亀山台場 | Hilltop | Ruins only | Edo Period | Yamaguchi Prefecture | Viewer Contributed | 2021 | |
| Kameyama Castle | Kameyama Castle | 亀山城 | Hilltop | No main keep but other buildings | Edo Period | Mie Prefecture | Viewer Contributed | 2008 | |
| Kameyama Castle (Azumi) | Kameyama Castle (Azumi) | 安曇亀山城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2019 | |
| Kameyama Castle (Kii) | Kameyama Castle (Kii) | 亀山城 | Mountaintop | Ruins only | Pre Edo Period | Wakayama Prefecture | 2023 | 2023 | |
| Kameyama Castle (Mikawa) | Kameyama Castle (Mikawa) | 三河亀山城 | Hilltop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kami Castle (Suwa) | Kami Castle (Suwa) | 諏訪上城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kamigare Castle | Kamigare Castle | 上狩宇城 | Fortified Manor | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2025 | |
| Kamigatou Yashiki | Kamigatou Yashiki | 上河東屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Kamigishimoto Castle (Omi) | Kamigishimoto Castle (Omi) | 近江上岸本城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2021 | |
| Kamihiraideko Castle (Ina) | Kamihiraideko Castle (Ina) | 伊那上平井出小城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kamiiida Jin'ya | Kamiiida Jin'ya | 上飯田陣屋 | Flatland | Ruins only | Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Kamijima Castle (Ina) | Kamijima Castle (Ina) | 小出上島城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Kamikurabara Fort | Kamikurabara Fort | 上蔵原塁 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Kamimakifuru Castle | Kamimakifuru Castle | 上牧古城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kaminagahara Castle | Kaminagahara Castle | 上永原城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kaminogou Castle | Kaminogou Castle | 上ノ郷城 | Hilltop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2022 | |
| Kaminoyama Castle | Kaminoyama Castle | 上山城 | Hilltop | Reconstructed main keep | Edo Period | Yamagata Prefecture | 1997
2017 | 1999 | |
| Kamioka Castle | Kamioka Castle | 神岡城 | Hilltop | Reconstructed main keep | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2011 | |
| Kamitohno Castle | Kamitohno Castle | 上遠野城 | Mountaintop | Ruins only | Pre Edo Period | Fukushima Prefecture | Viewer Contributed | 2016 | |
| Kamiwada Castle | Kamiwada Castle | 上和田城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kamo Castle (Bitchu) | Kamo Castle (Bitchu) | 備中鴨庄城 | Flatland | Ruins only | Pre Edo Period | Okayama Prefecture | Viewer Contributed | 2022 | |
| Kamogatake Castle | Kamogatake Castle | 鴨ヶ嶽城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kamomegasaki Battery (Obama Domain) | Obama Domain Kamomegasaki Battery | 小浜藩鴎ヶ崎台場 | Mountaintop | Ruins only | Edo Period | Fukui Prefecture | Viewer Contributed | 2023 | |
| Kan'onsaka Castle (Hanishina) | Kan'onsaka Castle (Hanishina) | 村上観音坂城 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Kanaiyama Castle | Kanaiyama Castle | 金井山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | 2016 | 2017 | |
| Kanao Yogaisan Castle | Kanao Yogaisan Castle | 金尾要害山城 | Mountaintop | Ruins only | Pre Edo Period | Saitama Prefecture | 2018 | 2018 | |
| Kanasashi Yakata | Kanasashi Yakata | 金刺館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Kanayama Castle | Kanayama Castle | 金山城 | Mountaintop | Ruins only | Pre Edo Period | Gunma Prefecture | 2007
2013 | 2007 | |
| Kanayama Castle (Echigo) | Kanayama Castle (Echigo) | 越後金山城 | Mountaintop | Ruins only | Pre Edo Period | Niigata Prefecture | Viewer Contributed | 2021 | |
| Kanazawa Castle | Kanazawa Castle | 金沢城 | Hilltop | No main keep but other buildings | Edo Period | Ishikawa Prefecture | 2006
2016
2020 | 2006 | |
| Kanbara Castle | Kanbara Castle | 鎌原城 | Mountaintop | Ruins only | Pre Edo Period | Gunma Prefecture | Viewer Contributed | 2022 | |
| Kanbayashi Castle | Kanbayashi Castle | 上林城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2024 | 2024 | |
| Kanbe Castle | Kanbe Castle | 神戸城 | Flatland | No main keep but other buildings | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2017 | |
| Kanegasaki Battery (Obama Domain) | Obama Domain Kanegasaki Battery | 小浜藩金ヶ崎台場 | Flatland | Ruins only | Edo Period | Fukui Prefecture | Viewer Contributed | 2023 | |
| Kanegasaki Castle | Kanegasaki Castle | 金ヶ崎城 | Mountaintop | Ruins only | Pre Edo Period | Fukui Prefecture | Viewer Contributed | 2015 | |
| Kanegasaki Castle (Iwate) | Kanegasaki Castle | 金ヶ崎城 | Flatland | Ruins only | Edo Period | Iwate Prefecture | 2018 | 2018 | |
| Kaneko Castle (Suwa) | Kaneko Castle (Suwa) | 諏訪金子城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kaneko Yashiki (Minochi) | Kaneko Yashiki (Minochi) | 水内金子屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Kanemaru Yakata | Kanemaru Yakata | 金丸館 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Kaneyama Castle (Mino) | Kaneyama Castle (Mino) | 美濃金山城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2021 | |
| Kaneyama Castle (Mutsu) | Kaneyama Castle (Mutsu) | 陸奥金山城 | Mountaintop | Ruins only | Pre Edo Period | Miyagi Prefecture | Viewer Contributed | 2017 | |
| Kanmuriyama Castle (Bitchu) | Kanmuriyama Castle (Bitchu) | 備中冠山城 | Mountaintop | Ruins only | Pre Edo Period | Okayama Prefecture | Viewer Contributed | 2022 | |
| Kannonji Castle | Kannonji Castle | 観音寺城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | 2011 | 2007 | |
| Kannosan Castle | Kannosan Castle | 神尾山城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2023 | 2024 | |
| Kano Castle | Kano Castle | 加納城 | Flatland | Ruins only | Edo Period | Gifu Prefecture | 2019 | 2020 | |
| Kanzeyamachi Battery (Obama Domain) | Obama Domain Kanzeyamachi Battery | 小浜藩観世屋町台場 | Flatland | Ruins only | Edo Period | Fukui Prefecture | Viewer Contributed | 2023 | |
| Kanzou Yashiki | Kanzou Yashiki | 甘草屋敷 | Fortified Manor | No main keep but other buildings | Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Karakai Castle | Karakai Castle | 辛垣城 | Mountaintop | Ruins only | Pre Edo Period | Tokyo | 2017 | 2017 | |
| Karasaki Castle | Karasaki Castle | 唐崎城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Karasawayama Castle | Karasawayama Castle | 唐沢山城 | Mountaintop | Ruins only | Pre Edo Period | Tochigi Prefecture | 2007
2018 | 2007 | |
| Karasuyama Castle | Karasuyama Castle | 烏山城 | Mountaintop | Ruins only | Edo Period | Tochigi Prefecture | 2015 | 2015 | |
| Karatoriya Castle | Karatoriya Castle | 唐鳥屋城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Karatsu Castle | Karatsu Castle | 唐津城 | Hilltop | Reconstructed main keep | Edo Period | Saga Prefecture | Viewer Contributed | 2006 | |
| Karidako Castle | Karidako Castle | 雁田小城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Karidaoh Castle | Karidaoh Castle | 雁田大城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Kariya Castle | Kariya Castle | 刈谷城 | Hilltop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2020 | |
| Kariyahara Castle | Kariyahara Castle | 刈谷原城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Kasama Castle | Kasama Castle | 笠間城 | Mountaintop | No main keep but other buildings | Edo Period | Ibaraki Prefecture | 2011 | 2011 | |
| Kasane Castle | Kasane Castle | 重ね城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2019 | |
| Kasashima Castle | Kasashima Castle | 笠島城 | Hilltop | Ruins only | Pre Edo Period | Kagawa Prefecture | Viewer Contributed | 2014 | |
| Kaseyama Castle | Kaseyama Castle | 鹿背山城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2023 | 2012 | |
| Kashima Castle (Hizen) | Kashima Castle (Hizen) | 肥前鹿島城 | Flatland | No main keep but other buildings | Edo Period | Saga Prefecture | Viewer Contributed | 2020 | |
| Kashiwabara Castle (Omi) | Kashiwabara Castle (Omi) | 近江柏原城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2021 | |
| Kashiwabara Palace | Kashiwabara Palace | 柏原御殿 | Flatland | Ruins only | Edo Period | Shiga Prefecture | Viewer Contributed | 2021 | |
| Kashiwara Castle | Kashiwara Castle | 柏原城 | Hilltop | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2016 | |
| Kashiwayama Castle (Murakami Clan Fort Network) | Kashiwayama Castle (Murakami Clan Fort Network) | 村上柏山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Kasuga Castle (Ina) | Kasuga Castle (Ina) | 伊那春日城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kasugayama Castle | Kasugayama Castle | 春日山城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Niigata Prefecture | 2011 | 2011 | |
| Kasumi Castle | Kasumi Castle | 霞城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | 2016 | 2016 | |
| Kasumiga Castle (Suwa) | Kasumiga Castle (Suwa) | 諏訪霞ヶ城 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Katahara Castle (Mikawa) | Katahara Castle (Mikawa) | 三河形原城 | Hilltop | Ruins only | Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Katakari Castle (Tanba) | Katakari Castle (Tanba) | 丹波鹿集城 | Fortified Manor | Ruins only | Pre Edo Period | Hyogo Prefecture | Viewer Contributed | 2021 | |
| Katakura Castle | Katakura Castle | 片倉城 | Hilltop | Ruins only | Pre Edo Period | Tokyo | 2015 | 2015 | |
| Katsumata Castle | Katsumata Castle | 勝間田城 | Mountaintop | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2024 | |
| Katsumoto Castle | Katsumoto Castle | 勝本城 | Hilltop | Ruins only | Pre Edo Period | Nagasaki Prefecture | Viewer Contributed | 2020 | |
| Katsunuma Castle | Katsunuma Castle | 勝沼城 | Mountaintop | Ruins only | Pre Edo Period | Tokyo | 2015 | 2015 | |
| Katsunumashi Yakata | Katsunumashi Yakata | 勝沼氏館 | Fortified Manor | Ruins only | Edo Period | Yamanashi Prefecture | 2017 | 2017 | |
| Katsurao Castle (Hanishina) | Katsurao Castle (Hanishina) | 村上葛尾城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Katsurayama Castle | Katsurayama Castle | 葛山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Katsuren Castle | Katsuren Castle | 勝連城 | Mountaintop | Ruins only | Pre Edo Period | Okinawa Prefecture | Viewer Contributed | 2008 | |
| Katsushima Castle (Omi) | Katsushima Castle (Omi) | 近江勝島城 | Flatland | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2020 | |
| Katsuyama Castle (Echigo) | Katsuyama Castle (Echigo) | 越後勝山城 | Mountaintop | Ruins only | Pre Edo Period | Niigata Prefecture | Viewer Contributed | 2021 | |
| Katsuyama Castle (Nagato) | Katsuyama Castle (Nagato) | 長門且山城 | Mountaintop | Ruins only | Pre Edo Period | Yamaguchi Prefecture | Viewer Contributed | 2021 | |
| Katsuyama Castle (Tsuru) | Katsuyama Castle (Tsuru) | 勝山城 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | 2019 | 2020 | |
| Katsuyama Castle (Yatsushiro) | Katsuyama Castle (Yatsushiro) | 八代勝山城 | Hilltop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Katsuyama Palace | Katsuyama Palace | 勝山御殿 | Flatland | No main keep but other buildings | Edo Period | Yamaguchi Prefecture | Viewer Contributed | 2021 | |
| Kattori Castle (Chikuma) | Kattori Castle (Chikuma) | 筑摩川鳥城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kawagoe Castle | Kawagoe Castle | 川越城 | Flatland | No main keep but other buildings | Edo Period | Saitama Prefecture | 2006
2012 | 2006 | |
| Kawahara Castle | Kawahara Castle | 河原城 | Hilltop | Reconstructed main keep | Pre Edo Period | Tottori Prefecture | Viewer Contributed | 2017 | |
| Kawajiri Castle | Kawajiri Castle | 川尻城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kawamura Castle | Kawamura Castle | 河村城 | Mountaintop | Ruins only | Pre Edo Period | Kanagawa Prefecture | 2014 | 2014 | |
| Kawamura Yakata | Kawamura Yakata | 河村館 | Fortified Manor | Ruins only | Pre Edo Period | Kanagawa Prefecture | Viewer Contributed | 2022 | |
| Kawanami Castle (Omi) | Kawanami Castle (Omi) | 近江川南城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kawanoe Castle | Kawanoe Castle | 川之江城 | Mountaintop | Reconstructed main keep | Pre Edo Period | Ehime Prefecture | Viewer Contributed | 2011 | |
| Kawasaki Battery (Obama Domain) | Obama Domain Kawasaki Battery | 小浜藩川崎台場 | Flatland | Ruins only | Edo Period | Fukui Prefecture | Viewer Contributed | 2023 | |
| Kawasaki Shoujirou Yakata | Kawasaki Shoujirou Yakata | 川崎庄司郎館 | Fortified Manor | Ruins only | Pre Edo Period | Tokyo | Viewer Contributed | 2022 | |
| Kawasaki no Saku | Kawasaki no Saku | 河崎柵 | Flatland | No main keep but other buildings | Pre Edo Period | Iwate Prefecture | Viewer Contributed | 2023 | |
| Kawashima Castle | Kawashima Castle | 川島城 | Hilltop | Reconstructed main keep | Pre Edo Period | Tokushima Prefecture | Viewer Contributed | 2013 | |
| Kawashimamurako Castle | Kawashimamurako Castle | 河島村古城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kawawada Castle | Kawawada Castle | 河和田城 | Flatland | Ruins only | Pre Edo Period | Ibaraki Prefecture | Viewer Contributed | 2018 | |
| Kaya Yakata | Kaya Yakata | 賀陽館 | Fortified Manor | Ruins only | Pre Edo Period | Okayama Prefecture | Viewer Contributed | 2022 | |
| Kazama Yakata | Kazama Yakata | 風間館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kazama Yashiki (Kai) | Kazama Yashiki (Kai) | 甲斐風間屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Kazue Yashiki (Nukata) | Kazue Yashiki (Nukata) | 額田主計屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Kazurayama Castle | Kazurayama Castle | 葛山城 | Mountaintop | Ruins only | Pre Edo Period | Shizuoka Prefecture | 2014 | 2014 | |
| Kazurayama Yakata | Kazurayama Yakata | 葛山館 | Fortified Manor | Ruins only | Pre Edo Period | Shizuoka Prefecture | 2014 | 2023 | |
| Keirozan Castle | Keirozan Castle | 鶏籠山城 | Mountaintop | Ruins only | Pre Edo Period | Hyogo Prefecture | 2012 | 2023 | |
| Kemi Castle (Chiisagata) | Kemi Castle (Chiisagata) | 小県花見城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Kemi Castle (Chikuma) | Kemi Castle (Chikuma) | 筑摩花見城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kemurino Castle (Murakami Clan Fort Network) | Kemurino Castle (Murakami Clan Fort Network) | 村上煙ノ城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Ken Castle (Kozuke) | Ken Castle (Kozuke) | 上野剣城 | Fortified Manor | Ruins only | Pre Edo Period | Gunma Prefecture | Viewer Contributed | 2021 | |
| Kesadaira Castle | Kesadaira Castle | 今朝平城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Kibune Castle | Kibune Castle | 木舟城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kibyu Castle | Kibyu Castle | 黍生城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Kido Castle (Mikawa) | Kido Castle (Mikawa) | 三河木戸城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2025 | |
| Kidoko Castle (Mikawa) | Kidoko Castle (Mikawa) | 三河木戸古城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2025 | |
| Kiga Jin'ya | Kiga Jin'ya | 気賀陣屋 | Hilltop | Ruins only | Edo Period | Shizuoka Prefecture | Viewer Contributed | 2024 | |
| Kikkawa Motoharu Yakata | Kikkawa Motoharu Yakata | 吉川元春館 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Hiroshima Prefecture | Viewer Contributed | 2020 | |
| Kikuchi Castle | Kikuchi Castle | 鞠智城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Kumamoto Prefecture | Viewer Contributed | 2009 | |
| Kimura Castle | Kimura Castle | 木村城 | Flatland | Ruins only | Pre Edo Period | Shiga Prefecture | 2021 | 2023 | |
| Kinebuchi Yakata | Kinebuchi Yakata | 杵淵館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Kinojo | Kinojo | 鬼ノ城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Okayama Prefecture | 2010 | 2011 | |
| Kinoshita Castle | Kinoshita Castle | 木ノ下城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kinowa Castle | Kinowa Castle | 城輪柵 | Flatland | No main keep but other buildings | Pre Edo Period | Yamagata Prefecture | Viewer Contributed | 2023 | |
| Kinzan Castle | Kinzan Castle | 金山城 | Mountaintop | Ruins only | Pre Edo Period | Hyogo Prefecture | 2024 | 2025 | |
| Kirarazaka Castle | Kirarazaka Castle | 雲母坂城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2021 | 2022 | |
| Kiridohshi Jin'ya | Kiridohshi Jin'ya | 切通陣屋 | Fortified Manor | Ruins only | Edo Period | Gifu Prefecture | Viewer Contributed | 2024 | |
| Kiridouzan Noroshidai | Kiridouzan Noroshidai | 霧訪山狼煙台 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kirihara Castle | Kirihara Castle | 桐原城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | 2015 | 2016 | |
| Kirihara Castle (Minochi) | Kirihara Castle (Minochi) | 水内桐原城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kirihara Yakata | Kirihara Yakata | 桐原館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kiriyama Castle | Kiriyama Castle | 霧山城 | Mountaintop | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2024 | |
| Kisai Castle | Kisai Castle | 騎西城 | Flatland | Reconstructed main keep | Pre Edo Period | Saitama Prefecture | Viewer Contributed | 2011 | |
| Kishiwada Castle | Kishiwada Castle | 岸和田城 | Flatland | Reconstructed main keep | Edo Period | Osaka | 2013 | 2006 | |
| Kiso Daikansho | Kiso Daikansho | 木曽代官所 | Flatland | No main keep but other buildings | Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kiso Yoshinaka Yakata | Kiso Yoshinaka Yakata | 木曽義仲館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kisotono Yashiki | Kisotono Yashiki | 木曽殿屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kissatsu Castle | Kissatsu Castle | 切差城 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2024 | |
| Kita Kumai Castle | Kita Kumai Castle | 北熊井城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2019 | |
| Kita Majino Castle | Kita Majino Castle | 北真志野城 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kita Tsuda Castle | Kita Tsuda Castle | 北津田城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kita Wakamiko Castle | Kita Wakamiko Castle | 北若神子城 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Kitaaranami Fort | Kitaaranami Fort | 北新波砦 | Flatland | No main keep but other buildings | Pre Edo Period | Gunma Prefecture | Viewer Contributed | 2022 | |
| Kitabatakeshi Yakata | Kitabatakeshi Yakata | 北畠氏館 | Fortified Manor | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2020 | |
| Kitabatakeshi Yakata Tsumenoshiro | Kitabatakeshi Yakata Tsumenoshiro | 北畠氏館詰城 | Mountaintop | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2025 | |
| Kitabodaiji Castle (Omi) | Kitabodaiji Castle (Omi) | 近江北菩提寺城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2021 | |
| Kitagata Castle (Ibi) | Kitagata Castle (Ibi) | 揖斐北方城 | Mountaintop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2021 | |
| Kitagata Castle (Motosu) | Kitagata Castle (Motosu) | 本巣北方城 | Flatland | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2025 | |
| Kitagata Jin'ya | Kitagata Jin'ya | 北方陣屋・本巣北方城 | Flatland | Ruins only | Edo Period | Gifu Prefecture | Viewer Contributed | 2025 | |
| Kitagejou Fort | Kitagejou Fort | 北下条塁 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Kitagejou Yashiki | Kitagejou Yashiki | 北下条屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Kitamura Castle (Omi) | Kitamura Castle (Omi) | 近江北村城 | Flatland | No main keep but other buildings | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kitano Castle (Ina) | Kitano Castle (Ina) | 伊那北ノ城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kitanosho Castle | Kitanosho Castle | 北ノ庄城 | Flatland | Ruins only | Pre Edo Period | Fukui Prefecture | 2006 | 2006 | |
| Kitanosho Castle (Omi) | Kitanosho Castle (Omi) | 近江北ノ庄城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kitasudayama Castle (Omi) | Kitasudayama Castle (Omi) | 近江北須田山城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kitatsumeno Fort | Kitatsumeno Fort | 北爪ノ砦 | Flatland | Ruins only | Pre Edo Period | Gunma Prefecture | Viewer Contributed | 2022 | |
| Kitsuki Castle | Kitsuki Castle | 杵築城 | Hilltop | Reconstructed main keep | Edo Period | Oita Prefecture | Viewer Contributed | 2011 | |
| Kitsune Castle (Azumi) | Kitsune Castle (Azumi) | 安曇狐城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kitsuneyashiki Yakata | Kitsuneyashiki Yakata | 狐屋敷館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kiyomizu Castle (Ina) | Kiyomizu Castle (Ina) | 伊那清水城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kiyosaki Castle (Echigo) | Kiyosaki Castle (Echigo) | 越後清崎城 | Flatland | Ruins only | Edo Period | Niigata Prefecture | Viewer Contributed | 2021 | |
| Kiyosu Castle | Kiyosu Castle | 清洲城 | Flatland | Reconstructed main keep | Pre Edo Period | Aichi Prefecture | 1995 | 1999 | |
| Kizu Castle | Kizu Castle | 木津城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2023 | 2024 | |
| Kobinata Oh'yashiki | Kobinata Oh'yashiki | 小日向大屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kobushi Castle (Tsuru) | Kobushi Castle (Tsuru) | 都留小伏城 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Kochi Castle | Kochi Castle | 高知城 | Hilltop | Original main keep | Edo Period | Kochi Prefecture | 2001 | 2001 | |
| Kodera Castle (Mino) | Kodera Castle (Mino) | 美濃小寺城 | Mountaintop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2025 | |
| Kofu Castle | Kofu Castle | 甲府城 | Hilltop | No main keep but other buildings | Edo Period | Yamanashi Prefecture | 2003
2007
2015
2017 | 2003 | |
| Koga Castle | Koga Castle | 古河城 | Flatland | Ruins only | Pre Edo Period | Ibaraki Prefecture | Viewer Contributed | 2022 | |
| Kogamine Castle (Kyoto) | Kogamine Castle (Kyoto) | 甲ケ峯城 | Mountaintop | Ruins only | Pre Edo Period | Kyoto | 2023 | 2024 | |
| Kogane Castle | Kogane Castle | 小金城 | Hilltop | Ruins only | Pre Edo Period | Chiba Prefecture | 2015 | 2015 | |
| Kogane Castle (Mikawa) | Kogane Castle (Mikawa) | 三河小金城 | Mountaintop | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kohyama Castle | Kohyama Castle | 香山城 | Mountaintop | Ruins only | Pre Edo Period | Hyogo Prefecture | 2023 | 2024 | |
| Koibuchi Castle | Koibuchi Castle | 鯉淵城 | Flatland | Ruins only | Pre Edo Period | Ibaraki Prefecture | Viewer Contributed | 2018 | |
| Koide Castle (Ina) | Koide Castle (Ina) | 伊那小出城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Koide Yakata (Tanba) | Koide Yakata | 小出館 | Fortified Manor | Ruins only | Edo Period | Kyoto | 2023 | 2024 | |
| Koike Fort | Koike Fort | 小池砦 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Koiwatake Castle | Koiwatake Castle | 小岩嶽城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kojima Castle (Hida) | Kojima Castle (Hida) | 飛騨小島城 | Mountaintop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2019 | |
| Kokokuji Castle | Kokokuji Castle | 興国寺城 | Hilltop | Ruins only | Pre Edo Period | Shizuoka Prefecture | 2014 | 2014 | |
| Kokura Castle | Kokura Castle | 小倉城 | Flatland | Reconstructed main keep | Edo Period | Fukuoka Prefecture | Viewer Contributed | 2006 | |
| Kokururi Castle | Kokururi Castle | 古久留里城 | Mountaintop | Ruins only | Pre Edo Period | Chiba Prefecture | 2021 | 2021 | |
| Kokuryou Castle (Omi) | Kokuryou Castle (Omi) | 近江国領城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kokuryou Castle (Tanba) | Kokuryou Castle (Tanba) | 丹波国領城 | Fortified Manor | Ruins only | Pre Edo Period | Hyogo Prefecture | Viewer Contributed | 2021 | |
| Kokuzousan Castle (Aida) | Kokuzousan Castle (Aida) | 会田虚空蔵山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Kokuzousan Castle (Murakami Clan Fort Network) | Kokuzousan Castle (Murakami Clan Fort Network) | 村上虚空蔵山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kokuzousan Noroshidai | Kokuzousan Noroshidai | 虚空蔵山烽火台 | Mountaintop | No main keep but other buildings | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kokuzousanminami Fort (Aida) | Kokuzousanminami Fort (Aida) | 会田虚空蔵山南砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Kokuzousannanseioneno Castle (Aida) | Kokuzousannanseioneno Castle (Aida) | 会田虚空蔵山南西尾根の城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Kokuzousannishi Fort (Aida) | Kokuzousannishi Fort (Aida) | 虚空蔵山西砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Komai Yashiki | Komai Yashiki | 駒井屋敷 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Komaki Castle | Komaki Castle | 小牧城 | Mountaintop | Reconstructed main keep | Pre Edo Period | Aichi Prefecture | 1996 | 1999 | |
| Komaki Castle (Chiisagata) | Komaki Castle (Chiisagata) | 小県小牧城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Komakijou Ohte Fort | Komakijou Ohte Fort | 小牧城大手砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Komakikamino Castle (Chiisagata) | Komakikamino Castle (Chiisagata) | 小県小牧上ノ城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Komaruyama Castle (Kiso) | Komaruyama Castle (Kiso) | 木曽小丸山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Komaruyama Fort (Murakami Clan Fort Network) | Komaruyama Fort (Murakami Clan Fort Network) | 村上小丸山砦 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Komasawa Castle | Komasawa Castle | 駒澤城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Komatsu Castle | Komatsu Castle | 小松城 | Flatland | No main keep but other buildings | Edo Period | Ishikawa Prefecture | 2020 | 2019 | |
| Komatsu Castle (Sagami) | Komatsu Castle (Sagami) | 相模小松城 | Mountaintop | Ruins only | Pre Edo Period | Kanagawa Prefecture | Viewer Contributed | 2023 | |
| Komatsuyama Noroshidai | Komatsuyama Noroshidai | 小松山烽火台 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Komazawa Castle (Minochi) | Komazawa Castle (Minochi) | 水内駒沢城 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Komesu Castle | Komesu Castle | 米須グスク | Hilltop | Ruins only | Pre Edo Period | Okinawa Prefecture | Viewer Contributed | 2023 | |
| Komihanachi Castle | Komihanachi Castle | 小見放城 | Mountaintop | Ruins only | Pre Edo Period | Fukui Prefecture | 2023 | 2023 | |
| Komiyama Yakata | Komiyama Yakata | 小宮山館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Komono Castle | Komono Castle | 菰野城 | Flatland | No main keep but other buildings | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2022 | |
| Komori Castle (Omi) | Komori Castle (Omi) | 近江小森城 | Flatland | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Komori Yakata (Sarashina) | Komori Yakata (Sarashina) | 更級小森館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Komoro Castle | Komoro Castle | 小諸城 | Hilltop | No main keep but other buildings | Edo Period | Nagano Prefecture | 2008 | 2008 | |
| Kongouji Castle (Murakami Clan Fort Network) | Kongouji Castle (Murakami Clan Fort Network) | 村上金剛寺城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Kongouji Castle (Omi) | Kongouji Castle (Omi) | 近江金剛寺城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Konishi Castle (Ina) | Konishi Castle (Ina) | 伊那小西城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Konodai Castle | Konodai Castle | 国府台城 | Hilltop | Ruins only | Pre Edo Period | Chiba Prefecture | 2021 | 2021 | |
| Konosumiyama Castle | Konosumiyama Castle | 此隅山城 | Mountaintop | Ruins only | Pre Edo Period | Hyogo Prefecture | 2013 | 2013 | |
| Koori Nishiyama Castle | Koori Nishiyama Castle | 桑折西山城 | Mountaintop | Ruins only | Pre Edo Period | Fukushima Prefecture | 2020 | 2021 | |
| Koraku Castle | Koraku Castle | 狐落城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Korin Castle (Ina) | Korin Castle (Ina) | 伊那狐林城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Koriyama Castle (Hiroshima) | Koriyama Castle | 郡山城 | Mountaintop | Ruins only | Pre Edo Period | Hiroshima Prefecture | 2018 | 2019 | |
| Koromo Castle | Koromo Castle | 拳母城 | Hilltop | No main keep but other buildings | Edo Period | Aichi Prefecture | 2020 | 2019 | |
| Koromogawa Date | Koromogawa Date | 衣川館 | Fortified Manor | Reconstructed main keep | Pre Edo Period | Iwate Prefecture | Viewer Contributed | 2023 | |
| Kosakajinja Yakata | Kosakajinja Yakata | 小坂神社館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Kose Yashiki (Kai) | Kose Yashiki (Kai) | 甲斐小瀬屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Kosema Castle | Kosema Castle | 古瀬間城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Koshibami Castle | Koshibami Castle | 小柴見城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Koshigoe Castle | Koshigoe Castle | 腰越城 | Mountaintop | Ruins only | Pre Edo Period | Saitama Prefecture | 2015 | 2015 | |
| Koshikou Castle (Chikuma) | Koshikou Castle (Chikuma) | 筑摩古司口城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kosobu Yakata | Kosobu Yakata | 小曽部館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Kosodeonzakijinja Castle | Kosodeonzakijinja Castle | 小袖御崎神社城 | Flatland | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Kosuge Castle | Kosuge Castle | 小菅城 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Kosugeyama Yakata | Kosugeyama Yakata | 小菅山館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Koteshiro Fort | Koteshiro Fort | 小手城砦 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2025 | |
| Kotsukuri Castle | Kotsukuri Castle | 木造城 | Flatland | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2024 | |
| Kotsukuriko Castle | Kotsukuriko Castle | 木造古城 | Hilltop | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2024 | |
| Koudaiji Fort | Koudaiji Fort | 光台寺塁 | Flatland | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Kouji Yakata | Kouji Yakata | 越氏館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Koujin'o Castle | Koujin'o Castle | 荒神尾城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Koujin'yama Castle (Ina) | Koujin'yama Castle (Ina) | 伊那荒神山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Koujin'yama Noroshidai | Koujin'yama Noroshidai | 荒神山烽火台 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Kouka Saburo Yashiki | Kouka Saburo Yashiki | 高家三郎屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2023 | |
| Koumyo Castle | Koumyo Castle | 光明城 | Mountaintop | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2025 | |
| Koumyoji Yakata | Koumyouji Yakata | 光明寺館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kouno Yashiki (Kai) | Kouno Yashiki (Kai) | 甲斐河野屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Kounomine Castle | Kounomine Castle | 髙嶺城 | Mountaintop | Ruins only | Pre Edo Period | Yamaguchi Prefecture | Viewer Contributed | 2012 | |
| Kounoshou Castle (Omi) | Kounoshou Castle (Omi) | 近江香庄城 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kouriki Castle (Mikawa) | Kouriki Castle (Mikawa) | 三河高力城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kouyama Castle (Bingo) | Kouyama Castle (Bingo) | 備後甲山城 | Mountaintop | Ruins only | Pre Edo Period | Hiroshima Prefecture | Viewer Contributed | 2020 | |
| Kouyama Castle (Nagato) | Kouyama Castle (Nagato) | 長門甲山城 | Mountaintop | Ruins only | Pre Edo Period | Yamaguchi Prefecture | Viewer Contributed | 2021 | |
| Koya Castle | Koya Castle | 小屋城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Koya Castle (Chikuma) | Koya Castle (Chikuma) | 筑摩こや城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Koyaba Castle | Koyaba Castle | 小屋場城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Koyama Castle | Koyama Castle | 小山城 | Hilltop | Reconstructed main keep | Pre Edo Period | Shizuoka Prefecture | 2011 | 2011 | |
| Koyama Castle (Kai) | Koyama Castle (Kai) | 甲斐小山城 | Hilltop | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Koyamura Yashiki | Koyamura Yashiki | 小屋村屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kozubeta Castle | Kozubeta Castle | 上津部田城 | Mountaintop | Ruins only | Pre Edo Period | Mie Prefecture | Viewer Contributed | 2024 | |
| Kozukue Castle | Kozukue Castle | 小机城 | Hilltop | Ruins only | Pre Edo Period | Kanagawa Prefecture | 2010 | 2010 | |
| Kozutsumi Castle | Kozutsumi Castle | 小堤城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kubo Castle (Mikawa) | Kubo Castle (Mikawa) | 三河久保城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Kubodera Castle | Kubodera Castle | 窪寺城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kubodono Yashiki | Kubodono Yashiki | 久保殿屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2022 | |
| Kuboe Castle (Omi) | Kuboe Castle (Omi) | 近江窪江城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kubota Castle | Kubota Castle | 久保田城 | Hilltop | No main keep but other buildings | Edo Period | Akita Prefecture | 2018 | 2011 | |
| Kubota Castle (Nukata) | Kubota Castle (Nukata) | 額田久保田城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kuboyashiki (Koka) | Kuboyashiki (Koka) | 公方屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | 2022 | 2022 | |
| Kuboyashikishi Castle (Koka) | Kuboyashikishi Castle (Koka) | 公方屋敷支城 | Mountaintop | Ruins only | Pre Edo Period | Shiga Prefecture | 2022 | 2022 | |
| Kugo Castle (Mikawa) | Kugo Castle (Mikawa) | 三河供御城 | Fortified Manor | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kukuri Castle | Kukuri Castle | 久々利城 | Mountaintop | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2021 | |
| Kukyudaira Castle (Mikawa) | Kukyudaira Castle (Mikawa) | 九久平城 | Mountaintop | Ruins only | Edo Period | Aichi Prefecture | Viewer Contributed | 2024 | |
| Kuma Castle | Kuma Castle | 熊城 | Mountaintop | Ruins only | Pre Edo Period | Yamanashi Prefecture | 2017 | 2017 | |
| Kumagawa Castle | Kumagawa Castle | 熊川城 | Mountaintop | Ruins only | Pre Edo Period | Fukui Prefecture | 2024 | 2025 | |
| Kumagawa Jinya | Kumagawa Jinya | 熊川陣屋 | Flatland | Ruins only | Edo Period | Fukui Prefecture | 2024 | 2025 | |
| Kumagura Yakata | Kumagura Yakata | 熊倉館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kumamoto Castle | Kumamoto Castle | 熊本城 | Hilltop | Reconstructed main keep | Edo Period | Kumamoto Prefecture | Viewer Contributed | 2005 | |
| Kunaishoyu Castle | Kunaishoyu Castle | 宮内少輔城 | Fortified Manor | Ruins only | Pre Edo Period | Kyoto | 2021 | 2022 | |
| Kuniyoshi Castle | Kuniyoshi Castle | 国吉城 | Mountaintop | Ruins only | Pre Edo Period | Fukui Prefecture | Viewer Contributed | 2023 | |
| Kuno Castle | Kuno Castle | 久野城 | Hilltop | Ruins only | Edo Period | Shizuoka Prefecture | Viewer Contributed | 2024 | |
| Kunohe Castle | Kunohe Castle | 九戸城 | Hilltop | Ruins only | Pre Edo Period | Iwate Prefecture | 2010 | 2010 | |
| Kunori Yakata | Kunori Yakata | 九之里館 | Fortified Manor | Ruins only | Pre Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kunou Castle | Kunou Castle | 久能城 | Mountaintop | Ruins only | Pre Edo Period | Shizuoka Prefecture | Viewer Contributed | 2021 | |
| Kurahone Castle | Kurahone Castle | 鞍骨城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kuraji Castle (Koka) | Kuraji Castle (Koka) | 倉治城 | Hilltop | Ruins only | Pre Edo Period | Shiga Prefecture | 2022 | 2022 | |
| Kuranomae Fort | Kuranomae Fort | 蔵之前塁 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Kurata Castle (Ina) | Kurata Castle (Ina) | 伊那倉田城 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kurihara Yakata | Kurihara Yakata | 栗原館 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Kurita Castle | Kurita Castle | 栗田城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed
2023 | 2020 | |
| Kuriyagawa no Saku | Kuriyagawa no Saku | 厨川柵 | Flatland | No main keep but other buildings | Pre Edo Period | Iwate Prefecture | Viewer Contributed | 2023 | |
| Kurobane Castle | Kurobane Castle | 黒羽城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Tochigi Prefecture | 2021
Viewer Contributed | 2018 | |
| Kuroda Daikansho | Kuroda Daikansho | 黒田代官所 | Flatland | No main keep but other buildings | Edo Period | Shizuoka Prefecture | Viewer Contributed | 2024 | |
| Kuroi Castle | Kuroi Castle | 黒井城 | Mountaintop | No main keep but other buildings | Pre Edo Period | Hyogo Prefecture | 2023 | 2020 | |
| Kurokawashi Castle (Koka) | Kurokawashi Castle (Koka) | 黒川氏城 | Mountaintop | Ruins only | Edo Period | Shiga Prefecture | 2023 | 2023 | |
| Kurono Castle | Kurono Castle | 黒野城 | Flatland | Ruins only | Pre Edo Period | Gifu Prefecture | Viewer Contributed | 2021 | |
| Kuruma Castle | Kuruma Castle | 来馬城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kuruma Castle (Hanishina) | Kuruma Castle (Hanishina) | 埴科車城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Kurumayama Castle (Hanishina) | Kurumayama Castle (Hanishina) | 埴科車山城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2023 | |
| Kurume Castle | Kurume Castle | 久留米城 | Hilltop | Ruins only | Edo Period | Fukuoka Prefecture | Viewer Contributed | 2013 | |
| Kururi Castle | Kururi Castle | 久留里城 | Mountaintop | Reconstructed main keep | Edo Period | Chiba Prefecture | 2005
2021 | 2005 | |
| Kusama Bizennokami Yakata | Kusama Bizennokami Yakata | 草間肥前守館 | Fortified Manor | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
| Kushiki Castle (Chikuma) | Kushiki Castle (Chikuma) | 筑摩櫛木城 | Flatland | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kushima Castle | Kushima Castle | 玖島城 | Hilltop | No main keep but other buildings | Edo Period | Nagasaki Prefecture | Viewer Contributed | 2009 | |
| Kushizaki Castle | Kushizaki Castle | 櫛崎城 | Hilltop | Ruins only | Pre Edo Period | Yamaguchi Prefecture | Viewer Contributed | 2021 | |
| Kutsukake Castle | Kutsukake Castle | 沓掛城 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | 2020 | 2020 | |
| Kutsukakemura Fort | Kutsukakemura Fort | 沓掛村砦 | Flatland | Ruins only | Pre Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kutsuki Izuminokami Jin'ya | Kutsuki Izuminokami Jin'ya | 朽木和泉守陣屋 | Flatland | Ruins only | Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kutsuki Shuzen Jin'ya | Kutsuki Shuzen Jin'ya | 朽木主膳陣屋 | Flatland | Ruins only | Edo Period | Shiga Prefecture | Viewer Contributed | 2022 | |
| Kuwabara Castle | Kuwabara Castle | 桑原城 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | 2007 | 2007 | |
| Kuwagatahara Noroshidai | Kuwagatahara Noroshidai | 鍬形原烽火台 | Mountaintop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2020 | |
| Kuwai Castle (Mikawa) | Kuwai Castle (Mikawa) | 三河桑谷城 | Flatland | Ruins only | Edo Period | Aichi Prefecture | Viewer Contributed | 2023 | |
| Kuwana Castle | Kuwana Castle | 桑名城 | Flatland | No main keep but other buildings | Edo Period | Mie Prefecture | Viewer Contributed | 2013 | |
| Kyara Palace | Kyara Palace | 伽羅御所 | Fortified Manor | No main keep but other buildings | Pre Edo Period | Iwate Prefecture | Viewer Contributed | 2023 | |
| Kyotoshin Castle | Kyotoshin Castle | 京都新城 | Flatland | Ruins only | Pre Edo Period | Kyoto | Viewer Contributed | 2020 | |
| Kyouraishi Yashiki | Kyouraishi Yashiki | 教来石屋敷 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Kyouraishiminbu Yakata | Kyouraishiminbu Yakata | 教来石民部館 | Fortified Manor | Ruins only | Pre Edo Period | Yamanashi Prefecture | Viewer Contributed | 2022 | |
| Machimura Fort | Machimura Fort | 町村砦 | Hilltop | Ruins only | Pre Edo Period | Nagano Prefecture | Viewer Contributed | 2021 | |
