What sumiyagura means
A sumiyagura is a turret built at a corner of a castle enclosure. Set on the angle where the stone walls turn, it watches the approaches along two walls and defends against attackers. Its walls usually have loopholes for guns and arrows and drop openings for hurling stones on anyone climbing the walls.
Most are two storeys, with two or three floors inside, and some castles had large three-storey corner turrets. At many castles that have lost their keeps, corner turrets survive to convey the castle's appearance. Records give their size by tiers and floors, as two tiers and three floors with traditional tiles; tiers are the roofs seen from outside, floors the levels within.
Reading the records and the castle
The south-west corner turret of Nagoya Castle, Aichi, of about 1612, two tiers with three floors and roofed in traditional tiles, is an Important Cultural Property. Osaka Castle preserves turrets including the Sengan and Inui turrets of 1620, designated together with the main gate and walls as Important Cultural Properties. The south corner turret of Matsuyama Castle, Ehime, a two-storey turret at the south-west corner of the linked keep complex, has hooded drop openings at the outer corners of its lower storey and a balustrade around its upper storey; it is a reconstruction of 1967 and a Registered Tangible Cultural Property.
Some corner turrets survive from the Edo period and others were reconstructed in the modern era. Articles should check the date and designation category in the record and state which applies.
References
- 大阪城 大手門｜国指定文化財等データベース（文化庁）
- https://kunishitei.bunka.go.jp/bsys/maindetails/102/2114
- 名古屋城 西南隅櫓｜国指定文化財等データベース（文化庁）
- https://kunishitei.bunka.go.jp/heritage/detail/102/1184
- 松山城南隅櫓｜国指定文化財等データベース（文化庁）
- https://kunishitei.bunka.go.jp/bsys/maindetails/101/00012995
Last verified: 2026.09.27