Ōzato Castle

Ōzato Castle, also known as Shimasoe-Ōzato Castle, is a historic Ryukyuan gusuku fortification situated in the Ōzato neighborhood of Nanjō City on Okinawa Island, Japan. Perched atop a tongue-shaped limestone hill approximately 150 meters above sea level near the island's southern east coast, the site features steep cliffs to the north and west. Constructed in the early 14th century by Ōzato Magiri Aji, the castle was built using traditional Ryukyuan limestone and wood. The complex originally spanned roughly 210 meters north to south and 270 meters east to west, protected by double walls with an inner stone barrier standing about six meters high. Today, the location exists as ruins but remains open to the public and holds the distinguished status of a National Historic Site of Japan, a designation granted by the central government in 2012 to preserve its cultural legacy.

The castle possesses significant historical importance as the stronghold of Ōzato Ofusato, who declared himself the King of Nanzan in 1314 after breaking away from the chieftain at Urasoe Castle. During the Sanzan period, it served as a secondary castle to Nanzan Castle until the latter fell in 1429. Prior to this unification, the fortress was captured in 1402 by Shō Hashi of Sashiki Gusuku, bringing it under the influence of the First Shō Dynasty. Following this conquest, it functioned as a detached palace comparable in stature to Shuri Castle until at least the mid-15th century. Historical records note that a Qing dynasty investiture envoy visited the abandoned site in 1683, marking its transition from a political center to a historical monument. Although the main hall is now reduced to foundation stones, substantial stonework from the outer walls remains visible, offering visitors a tangible connection to the region's feudal past.