In 1951, stone tools were discovered in the area, which led to excavations and surveys, which revealed the existence of Paleolithic remains older than the Jomon period. This is the first survey of its kind in the southern Kanto region and the second in the whole country, and it is a memorable site that clarified the Paleolithic period not only in Tokyo but also in the Japanese archipelago. Part of the site is designated as a historic site (archaeological) by the Tokyo Metropolitan Government, and is also recognized as a registered monument in Itabashi Ward. Currently, the site is closed to visitors for protection.