It is considered that in this place, there was a port on Fukatsu Bay coast (the place was called 'Fukatsu Province' until early-modern times) which prospered as an outer harbor of the Kokufu (ancient provincial office/capital) in Bingo Province, and they are valuable ruins of the Ritsuryo era.
これは当地が備後国の国府の外港として栄えていた深津湾岸（近世までの郡名は「深津郡」）の港が存在していたとされており、律令時代の貴重な遺跡といえる。