Tagoyano Shell Midden is an early and middle Jōmon period archaeological site with an area about 14,000 square meters.  The first excavation was made in 1928 by Jujiro Nakaya and Fujio Imai. In 1990 and 1991, major excavation and research were conducted by the Prefectural Museum and remains of a pit-house in the early Jomon period was discovered.Cylindrical pottery from the early to middle Jomon period have been unearthed and later followed by pottery, stoneware, stone products, earthenware, bone horns, shell rings, etc. The midden is almost exclusively made of Japanese basket clams which were harvested from the brackish water and is a rare example of a shell midden to be found near the coast of the Sea of Japan.