Ōta Dōkan is best known as the…

Ōta Dōkan is best known as the architect and builder of Edo Castle (now the Imperial Palace) in what is today modern Tokyo.

A samurai warrior-poet, military tactician and Buddhist monk, he is considered the founder of the castle town which is to grow up around that Ōnin era fortress.

Instead of stone walls, the defense works around the fifteenth century castle are only grassy embankments, and the structures inside them are not grand.

The initial enclosure which serves as the castle's core area, the space which would have been Dōkan's hon-maru, is modestly sized; but the moats are extensive for this time.

These moats and their locations will figure prominently in the serial phases of construction and development that follow.