The “Ninomon Gate” plays an important role as the last gateway to the main citadel. The gate is covered with iron plates on all sides, from the gateposts, coronet, and large door to the side door, in preparation for fire. The gate is topped by a complex of three turrets, the interior of which consists of a low-ceilinged passageway that turns to the right and leads up a flight of stairs. This design delays the entry of attackers and facilitates defense from the upper turrets. In particular, by removing the floorboards of the turrets, it is possible to attack directly over the heads of enemy soldiers attempting to pass through the gate. Thus, the “Ninomon” is known as one of the best defensive and offensive turret gates in Himeji Castle.