Lake Penketo

Lake Penketo takes its name from the Ainu language, meaning "upper swamp." It sits in the eastern foothills of Mt. Oakan and connects via a single river to the larger Lake Panketo to the north. The three lakes in this area, Penketo, Panketo, and Akan, were once a single large body of water before volcanic activity from Mt. Oakan split them apart around 10,000 to 6,000 years ago. At 3.9 kilometers in circumference and 39 meters deep, Penketo is the smallest of the three. To protect its natural environment, public access to the lake shore is generally restricted, but both Penketo and Panketo are visible from the Sokodai Observatory.