Historical remains of the Sendai clan's fort in Shiraoi

The historical remains of this fort complex are located in Shiraoi and date to the Edo period, with foundations of military installations, storage areas, and administrative structures visible across the site. The ruins span a large area and reveal how different functional zones were organized together.

The Sendai clan established this fortified installation in 1856 to protect the region from potential Russian expansion during a period when Japan was strengthening its borders. This construction marked one of the final military projects undertaken during the nation's isolation policy.

The site displays the architectural qualities of a jin'ya, an administrative structure that served as regional power centers during Japan's feudal era. The layout shows how these buildings combined civil governance with military readiness.

The site is now partially accessible with visible stone foundations and a museum offering information about the former garrison and its operations. It helps to research beforehand since not all areas are fully restored or marked.

This was the largest military installation constructed in Hokkaido during the final years of Japan's isolation policy, housing about 150 to 200 samurai warriors. The fort's scale reflects its strategic importance for defending Japan's northern frontier at that critical historical moment.