Historic Sites Located on Depositional Landforms Created by Rock Avalanches
Among the flow hills formed by the Okinashima rock avalanche, the Hōshōjiri Ruins, where Jomon-period artifacts designated as National Important Cultural Properties were excavated, and the Hōshōjiri Wetland, known for its colonies of fringed orchids (Sagisō), can be found.
One of the flow hills formed by the same Ongashima rock avalanche is Ongashima, the only island in Lake Inawashiro, also known as Kamishima. This island was once used as a private beach by the Imperial Family. Additionally, the Imperial Family’s villa, Tenkyo-kaku, and the guesthouse are also located in the area.