Daigigakoi Shell Mound

Daigigakoi Shell Mound is an archaeological site on the south shore of Matsushima Bay shaped like a horseshoe when viewed from above. The mound preserves eight pit dwellings along with scattered remains of bones, shells, pottery pieces, and stone tools from ancient times.

The site preserves remains from the early to middle Jōmon period, roughly 4000 to 2500 years ago. During that era, ocean levels stood much higher than today, making the coastal zone an attractive place for settlement and food gathering.

Excavations revealed eight pit dwellings and numerous artifacts including bone materials, shells, pottery fragments, and stone tools that document ancient Japanese coastal life.

The site sits 35 meters above the current waterline and is accessible by car from nearby transportation points in the area. Walking around the grounds gives you a clear view of how the ancient settlement was laid out across the slope.

The mound reaches over 2 meters (6 feet) thick, making it one of the thickest deposits of shells and settlement remains found in the region. This unusual depth helps researchers compare and date other archaeological sites from the same period across southern Tōhoku.