22 TONASHI MON Gate (Doorless Gate – important cultural property).

This gate is a KOHRAIMON gate, that is, it consists of two pairs of pillars, and is so named because it has no door. Some people believe this is because the plan was to let the enemy go through this gate easily and attack the next gates of TSUTSUI MON Gate and the Hidden Gate, where they could be surrounded and countered completely. This gate, TSUTSUI MON Gate, and Hidden Gate are the most important defense points against frontal attack and attack from the areas of the intermediate and outermost outworks of the castle.