Namioka Castle, Mountain castle ruins in Aomori, Japan

Namioka Castle is a hilltop castle in Aomori with eight enclosures separated by double moats 10 to 30 meters wide. The main enclosure, the Uchi-no-tate, measures about 120 by 85 meters and contained the lord's residence. The site also preserves earthen ramparts and moat traces, and a white sign with black Japanese characters marks its designation as a national historic site.

Built in the 1460s by Kitabatake Akiyoshi of the Namioka Kitabatake clan, the castle fell in 1578 when Ōura Tamenobu attacked; the clan head Kitabatake Akimura was captured and later took his own life. In 1940 it became Aomori Prefecture's first national historic site, and in 2017 it was added to the Continued Top 100 Japanese Castles.

The castle served as a regional power center and administrative hub for the surrounding communities during medieval times. Today, visitors can observe the layout of residential and defensive areas that shaped daily life for those who lived within its walls.

The ruins lie about 15 minutes on foot from JR Namioka Station on the Ōu Main Line, or roughly 15 minutes by car from the Tōhoku Expressway's Namioka interchange. The site is a grassy, uneven hill with earthen ramparts and ditch lines, so sturdy shoes help. Dogs may be walked on the grounds.

Excavations at this site have uncovered thousands of medieval objects including weapons, tools, and household items scattered throughout the ruins. These artifacts provide direct evidence of how ordinary people lived their daily lives within the castle grounds.