The Iwakiri Castle was a castle that once stood in the city of Sendai in Miyagi Prefecture. The castle was built by the Rusu family, the Rusushiki (caretaker) of the Mutsunokuni region (present day Tohoku) during the Nanboku-cho Period (1333-1393). Later on, during a power struggle between Ashikaga Takauji and his older brother Ashikaga Tadayoshi, the Rusu family took sides with the Takauji faction, and the Iwakiri battle broke out.  Although the Takauji faction managed to hold  Iwakiri castle, in 1351, the Tadayoshi faction released a relentless full frontal attack, leading to the suicide of Okushu Kanrei and Hatakeyamashi, as well as the surrender of the Rusu family. Even after this defeat, the Rusu family continued to reside in Iwakiri castle up until Rusu Masakage became head of the family. Rusu Masakage moved the stronghold to Rifu castle in 1570; this move began the gradual deterioation of Iwakiri castle.
Currently, the area is covered with cedar forests and a grove of mixed tree copse; the only reminders of the former castle are a few horikiri (dry moats) and earthwork foundations. However the scenery of the Taihakusan and the Zaou Peaks is beautful, and the area has become known for its cherry blossoms during the spring. The Iwakiri castle is representative of the medieval castles in the Touhoku district, which exhibit a lot of historical dignity and honor.