Kosegasawa Cave

Kosegasawa Cave is an archaeological site within a rhyolite outcrop beside the Muroya River, extending about 7 meters into the rock formation. The cave entrance measures roughly 1.5 meters across and sits at an elevation of around 200 meters.

The site holds evidence from the earliest stages of the Jomon Period, uncovered through excavations conducted in the late 1950s. These early findings demonstrate that people inhabited this region during a time when hunting and gathering were the primary ways of life.

The site received national recognition in 1982 as a Historic Site of Japan, with 1350 artifacts later designated as National Important Cultural Property.

The site sits near Tsugawa Station and is reachable by car, making it accessible for visitors interested in archaeology. It helps to bring suitable clothing and sturdy shoes since the area is natural and the terrain may be uneven.

Certain stone tools discovered in the cave resemble artifacts from the distant Primorsky region in eastern Siberia. This connection suggests that there may have been contact or exchange between these far-apart areas during prehistoric times.

Location: Aga

GPS coordinates: 37.59222,139.40500

Latest update: December 14, 2025 09:44