The surrounding moat is approximately 5.45 meters in width and the earth dug up during excavation of that moat was piled up to build dorui (earthen walls) which seemed to have a total of nine gates that serviced the north, south, east and west ends of the town.
この環濠は巾三間（約5.45m）を有し、同環濠を掘り上げた際の建設発生土を盛り上げて土塁を築き、東西南北に九つの門を開けていたようである。