Shiryōkaku

thumb|right|250px|Aerial photography|Aerial photograph of Shiryōkaku, courtesy of National Land Image Information (Color Aerial Photographs), Ministry of Land, Infrastructure, Transport and Tourism (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. 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.