Yamanaka Castle, located at the northeast of Mishima city (Shizuoka Prefecture), was a Sengoku period mountain castle. Today there are no buildings or structures remaining. It was built by Hοjο Ujiyasu in the Eiroku era (1558–1577), to guard the western approaches to the clan’s primary castle, Odawara Castle. The site was also chosen for its strategic location overlooking the Tοkaidο, the main highway connecting the eastern provinces of Japan with the capital at Kyoto. During the 1590 Battle of Odawara, Toyotomi Hidetsugu led a force of 70,000 warriors against Yamanaka Castle, which was defended by Hojo Ujikatsuwith only 4,000 troops. Despite the disparity in numbers, the Toyotomi forces took heavy losses, including one general, Hitotsuyanagi Naosue; however, the castle fell in only a half day of combat and most of its defenders were killed.
On a clear day you can see Mt. Fuji.