The latter half of the Muromachi period was the Sengoku period (period of warring states) when warfare broke out all over Japan, making some villagers decide to build moats around their settlements in order to protect themselves from assaults.
室町時代の後半の戦国時代(日本)では戦乱が多発し、農村では集落を守るために周囲に堀（環濠）を巡らして襲撃に備えるところが現れた。