Back then, Imai-go was a village surrounded by a moat and earthen walls for fortification to defend itself against enemies outside as well as to protect autonomy of the village people, and the ruins of that moat still remain in existence around Imai today.
このとき今井郷の形態は、外敵と郷民の自治を守るために、郷の周辺に濠を巡らし、土塁を設けた環濠集落で、現在もその濠跡が今井の周辺にその遺構を残している。