Jomon people, the ancestors of modern Japanese, built the Isedotai site approximately 4,000 ago. The site centers on large four large stone circles and includes burial sites and traces of buildings. It is thought that the stone circles were a place of prayer and worship. Nearly 200 clay figures have been excavated from the site over the years which archaeologists believe were smashed during ceremonies. Only one intact figure has been found to date. Visitors can view the excavated figures at the Isedotai Museum and also take a guided walk of the stone circles.