TAIKO MON Gate, TAIKO connected turret, TAIKO Turret and TATSUMI (Southwest) Turret comprise one unit of defense, standing on a 6.9m (22.6 feet) stone wall. They provide strong defense against enemies who intrude through TSUTSUI MON Gate. On the west point of the stone wall lies TAIKO Turret. There was a 24.4m (80 feet) long fence between TAIKO MON Gate and TAIKO Turret, which stands on the west edge of the stone wall. 16 gun turrets and three points for dropping stones on the enemy were incorporated in this long fence.