The Hanzo-mon Gate, also called the “Kojimachiguchi Entrance,” was one of the inner gates of Edo Castle. It was built in 1620 by either Date Masamune, or the six daimyo (feudal lords) of the eastern provinces. It was one of the key points on the Keishii Kaido, the road that connected Edo (Tokyo) with Kai Province (now Yamanashi Prefecture).
It is said that got its name from the leader of the Iga Ninja Clan, Hattori Hanzo who was given residence and land in this area, along with his followers.
It is used as a side gate to the Imperial Palace of the Emperor.
