was a castle built in Mino Province in Japan during the late-Heian period (late 12th century); it was destroyed during the Sengoku period in the mid-16th century. The castle's ruins are located in the present-day city of Gifu, Gifu Prefecture. It stood at the peak of Mount Sagi, which was only . Because the castle was built as a residence and not a defensive fortress, its location on a small mountain was of little consequence.