Shiryōkaku

File:Shiryōkaku.jpg of Shiryōkaku, courtesy of National Land Image Information (Color Aerial Photographs), Ministry of Land, Infrastructure, Transport and Tourism]]

{{nihongo|Shiryōkaku|四稜郭}} (literally, "four-point fort") is a fort in the city of Hakodate in southern Hokkaidō, Japan. It was constructed in April 1869, during the Battle of Hakodate, three kilometres to the northeast of Goryōkaku by two hundred soldiers of the former Tokugawa shogunate and a hundred local villagers, likely under the direction of Ōtori Keisuke.{{cite web |url=http://www.city.hakodate.hokkaido.jp/soumu/hensan/hakodate-map/map-14.htm |archive-url=https://archive.today/20121219140403/http://www.city.hakodate.hokkaido.jp/soumu/hensan/hakodate-map/map-14.htm |url-status=dead |archive-date=19 December 2012 |title=四稜郭 |trans-title=Shiryōkaku |language=Japanese |publisher=Hakodate City |accessdate=21 June 2012 }} Shiryōkaku has four bastions , and is sometimes known as the "butterfly fort" as opposed to the "star fort".

The designated historic site area is 21,500 m², while the fort itself covers approximately 2,300 m², stretching approximately a hundred metres east to west and seventy metres north to south; the earthworks rise to a height of 3 m with a width of 5.4 m; they are surrounded by a dry moat 0.9 m deep and 2.7 m wide; the entrance is to the southwest.{{cite web |url=http://www.pref.hokkaido.jp/kseikatu/ks-bsbsk/bunkashigen/parts/10539.html |title=四稜郭 |trans-title=Shiryōkaku |language=Japanese |publisher=Hokkaidō Prefecture |accessdate=21 June 2012 |url-status=dead |archiveurl=https://web.archive.org/web/20121207185538/http://www.pref.hokkaido.jp/kseikatu/ks-bsbsk/bunkashigen/parts/10539.html |archivedate=7 December 2012 }}

Shiryōkaku fell to government forces within a few hours on 11 May 1869.{{cite web |url=http://www.city.hakodate.hokkaido.jp/board_of_edu/lifelong_learning/museum/collection/bunka/1_02.html |title=四稜郭 |trans-title=Shiryōkaku |language=Japanese |publisher=Hakodate City |accessdate=21 June 2012 |url-status=dead |archiveurl=https://web.archive.org/web/20120605083941/http://www.city.hakodate.hokkaido.jp/board_of_edu/lifelong_learning/museum/collection/bunka/1_02.html |archivedate=5 June 2012 }}

In 1934 the area was designated an Historic Site.{{cite web |url=https://kunishitei.bunka.go.jp/heritage/detail/401/14 |title=四稜郭 |trans-title=Shiryōkaku |language=Japanese |publisher=Agency for Cultural Affairs |accessdate=21 June 2012}} Repairs were carried out from 1970-2 and again in 1990.