Here are Hiroshige Utagawa’s Kagurazaka in Ukiyoe and the present picture of the place that Utagawa drew.
We can see the the gate to Edo castle as circled with red line.Hiroshige Utagawa Ushigomekagurazaka
In the present picture, I also draw a red circle around the top of the hill where the gate to the castle was located.
Actually, we can see the remain of the stone gate beside JR IIdabashi station west exit. The outer moat is next to the remain of the gate. In spring, a lot of cherry blossoms bloom along the moat. We can enjoy the view of the moat sipping coffee at a cafe along the moat.