Two-story turrets were normally used in modern citadels and small three-story turrets were used for large castles for the sumi yagura (corner towers) that were built at corners of a citadel, but were cases in which a turret that had a structure equivalent to tenshu (castle tower) were built, for example, the three-story turret in the honmaru (the keep of a castle) of Osaka-jo Castle and the five-story turret in Kumamoto-jo Castle.
郭の角にある隅櫓は、近世城郭では通常二重櫓、大きな城などでは小規模な三重櫓が用いられることもあったが、中には大坂城本丸にあった三重櫓や熊本城にある五階櫓のように天守に匹敵する構造を持つ櫓があげられていた例がある。