... was one of the gates of Edo Castle. It was Masugata gate, the square gate, and located the outer moats. Stones of the gate are still existed.
Benkei Moat
... is one of the outer moat of Edo Castle.
Kuichigai Gate
... was another ruins of the gate where Iwakura Tomomi, one of the Meiji Restoration heros, was assaulted here.
Kioizaka
is where Okubo Toshimichi, one of the three heros of Meiji Restoration was assassinated here in 1878.