Ichinosawa Caves
The Ichinosawa Caves (Ichinosawa dōkutsu) is an archaeological site containing the ruins of a Jōmon period cave dwelling located in what is now the northern part of the town of Takahata, Yamagata in the Tōhoku region of Japan. The site was designated a National Historic Site of Japan in 1980.
Cave data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).