Sakuradamon Gate

Sakuradamon Gate, completed around 1620, is the largest surviving gate of Edo Castle. Its design is a square masugata defense system: a small koraimon gate leads into an enclosed space, forcing intruders to turn before reaching the larger yaguramon gate above, where archers could attack from height. The enormous stones, mostly sourced from the Izu Peninsula 100 kilometers away, were brought by boat and fitted without mortar. In 1860, the gate became the site of the Sakuradamon Incident, when the shogunate's chief minister Ii Naosuke was assassinated here by imperial loyalist samurai. It is a designated Important Cultural Property.