Shiwa Castle Ruins, Morioka.

“Shiwa Castle was an early Heian period jōsaku-style Japanese castle located in what is now part of the city of Morioka, Iwate Prefecture in the Tōhoku region of far northern Honshu, Japan. The site was proclaimed a National Historic Site of Japan in 1979. Shiwa Castle was a square enclosure, approximately 840 metres (2,760 ft) on each side, consisting of an earthen rampart surmounted by a wooden palisade, and protected by a dry moat measuring 980 metres (3,220 ft) on each side.”