Sakasai Castle

Sakasai Castle was built during the Sengoku period by the Sakasai clan, who ruled southern Shimosa Province (now the Ibaraki-Chiba border region). This Sengoku-period flatland fortress was protected by a river on one side and a lotus marsh on the other. In 1536, during the Hōjō clan's campaign to unify the Kanto region, the castle fell after its lord Tsuneshige was killed in battle. Under Hōjō rule, the castle served as the easternmost frontier fortress against eastern powers such as the Satake and Yuki clans. Several hundred Fuuma ninja members are said to have been stationed within the castle. Following archaeological surveys in the 1980s, during which foundation stones were discovered, buildings, earthen walls, and watchtowers were reconstructed based on historical records in the 1990s. Today the castle uniquely preserves nearly its original Sengoku-period form, which is rare among flatland castles.