[2][3] The Togariishi stone age ruins (尖石石器時代遺跡, Togariishi sekki jidai iseki) is an archaeological site containing the ruins of a large scale Jōmon period settlement located in the Toyohira neighborhood of the city of Chino, Nagano.

[4] Despite the designation “Stone Age” in its name, the site has no connection with the Japanese Paleolithic period.

The site is located on along plateau at the foot of Mount Yatsugatake at an elevation of 1000 meters.

The area around Mount Yatsugatake has a very high concentration of Jōmon period ruins, partly because of abundant spring water and over 50 mid-Jōmon sites have been identified in the near vicinity of the Togariishi site.

At that time, the foundations of 33 pit dwellings arranged in a U-shape around a central plaza were discovered, along with numerous artifacts, including Jōmon pottery, stone tools, jewelry and obsidian tools.