Hijiyama

Elevation: 71.1m Hijiyama Shell Mound, a prefecturally designated historic site within Hijiyama Park, is home to shell mounds where people lived from the late Jomon period to its final years. During this period, the flow of the Ota River began to form a delta with a topography similar to that of today, and remains of the Jomon people who lived off the rich natural environment of seafood from the shallow waters and acorns and other mountain produce have been confirmed. Pottery excavated from the Hijiyama Shell Mound is said to have been used by people from the late Jomon period to boil nuts collected in deep bowls and use them as food. The shell mound itself is made up of two layers, and is said to tell the story of how Hijiyama, originally a small island, was absorbed into the Ota River Delta, where fresh water mixed in.