Agena Castle

Agena Castle, also known as Agina Gushiku in the Okinawan language, is a historic Ryūkyūan gusuku fortification located in the Agena district of Uruma, Okinawa Prefecture, Japan. Constructed in the early 14th century by Ōgawa Aji, the structure sits atop a Ryūkyūan limestone outcrop at an altitude of 49 meters, naturally defended by the Tengan River to the north. The castle covers an area of approximately 8,000 square meters and features massive stone walls ranging from two to over ten meters in height. Unlike the linear renkaku style common to most Okinawan gusuku, Agena Castle exhibits a rare kakushiki architectural style, characterized by a central enclosure surrounded by additional enclosures on the hillside. A distinctive feature of the site is its arched stone gate, which was carved directly into the natural rock wall connecting the outer and inner baileys.

Historically, the castle served as a significant political center during the Sanzan period and beyond. It was occupied for several generations by the Ōgawa Aji, who were male descendants of King Eiso and ruled central Okinawa Island from the 15th through the 16th century. Later, it also housed the Aji of Gushikawa Magiri. The site remained in use until the 15th century before eventually falling into ruin. Today, the location is recognized for its cultural importance and has been designated a National Historic Site of Japan since 1987 by the central government.

Currently, the castle exists as ruins but remains accessible to the public. The grounds have been repurposed as Agena Park, which uniquely incorporates a bullring within the former castle boundaries. Despite its ruined condition, the site preserves impressive examples of Ryūkyūan stonework and offers insight into the region's feudal history. Visitors can explore the remnants of the fortification while learning about the powerful local lords who once commanded this strategic stronghold in the Ryūkyū Kingdom.