Lake Shikotsu in Shikotsu-Toya National Park in Hokkaido is Japan’s second largest caldera lake with a circumference of 42 km. It was formed as the result of an volcanic eruption about 32,000 years ago. With the average water temperature of 3.6 degrees, it is Japan’s coldest ice-free lake. It is also one of the most transparent lakes in Japan and is the second deepest lake, after Lake Tazawa, with a maximum depth of 363 m, which is 115 deepr than the sea level. The lake is surrounded by the 1,000-meter-class mountains including Mt. Eniwadake, Mt. Fuppushidake and Mt. Tarumae.

Around the lake spread the deep green virgin forests of broad-leaved deciduous trees such as maple (Acer mono) and oak and conifer trees such as Jezo spruce. It is also a popular spot for bird watching. Wild birds such as great spotted woodpeckers and black woodpeckers can be seen.

In contrast to the bustle of the streets in Toyako hot spring town, here, everything is in the deep tranquility of the unexplored forests.