The third largest caldera lake in Japan

The beautiful Lake Toya is the central lake of Shikotsu-Toya National Park and is the third largest caldera lake in Japan after Lake Kussharo and Lake Shikotsu in Hokkaido. Formed by a massive eruption approximately 110,000 years ago, the lake has a circumference of approximately 43km (road circumference of approximately 36km), a water surface elevation of 84m, an area of 70.7km², and an average depth of 117m. It is the northernmost lake that never freezes over, but in recent years, with the harsh cold, parts of it have frozen over.

The four islands in the center of the lake (Oshima, Bentenjima, Kannonjima, and Manjujima) are said to have formed from lava domes that rose during volcanic activity on the lake floor about 50,000 years ago, and are collectively known as Nakajima. You can see the beautiful Mt. Yotei to the north of Lake Toya, and the volcanoes Mt. Usu and Mt. Showa Shinzan to the south, and enjoy a variety of scenery throughout the four seasons.