| On March 28, 2008, a national historical site covering a wide area was newly designated as the 'Hiki-jo Castle Ruins,' comprised of the former Sugaya-yakata Castle site in addition to the former Matsuyama-jo Castle (Musashi Province) the Sugiyama-jo Castle and the Ogura-jo Castle (Musashi Province). |
2008年（平成20年）3月28日、菅谷館跡に松山城 (武蔵国)跡、杉山城跡、小倉城 (武蔵国)跡が加わり「比企城館跡群」としてあらためて国の史跡として広域指定された。 |