Located opposite side of recently renewed Place Hotel in Uchibori-dori, or near from the grave of Taira no Masakado’s head depicted in Teito Monogatari.
Entered from Otemon, the main gate of Edo Castle (not the Imperial Place), used for Tokugawa vassals(Daimyos) and it has “Masugata-mon”(square-shaped gate) to enclose enemies to be aimed from the gunports.
There are two stations, one for guards(Doshin-Bansho), and the other is for mobile units (Hyakunin-Bansho), at where any of vassals are asked to go in further on foot (not on horses).
Surrounded by warlords’ compounds, the security would be the priority for Tokugawa clan, I imagine.