In Higashikaizuka among the Tsutsumi Shell Mound, like Nishikaizuka, which has already been designated as a prefectural site, shell beds and pit dwelling sites have been confirmed, and earthenware, fish hooks, and shell rings have also been excavated. It is a site that shows the aspect of settlement and activities in the late Jomon period, and is recognized as one of the few shell middens from the late Jomon period left in the Sagami Bay area.