Site feature (8)
The North Valley was a garbage pit in the early Jomon period (approximately 5,500 to 5,000 years ago).
The moisture-rich soil has permitted the discovery in good condition of organic remains which otherwise would have decomposed such as animal and fish bones, plant seeds, lacquerware, wooden artifacts, woven objects, and parasite eggs. These remains have revealed the environment and diet of that time period. Piles for retaining soil have also been found in the North Valley.