Lake Shikotsuko

Lake Shikotsuko (支笏湖) and nearby Lake Toyako are the two most prominent features of the Shikotsu-Toya National Park. Both lakes are caldera lakes, which were formed from collapses in the earth after volcanic activity.

Most of Shikotsuko is little developed except for Shikotsu Kohan, a small, touristy town with a visitor center some lodgings along the lake's western shores. From there, visitors can rent boats, bicycles or scuba gear to enjoy the natural surroundings or join a sightseeing cruise of the lake in glass-bottomed boats or speed boats from late April to early November.

Lake Shikotsuko is encircled by mountains, one of which is Mount Tarumae. Tarumae ranks among Japan's most active volcanoes and most recently erupted in 1981. The mountain can be climbed in a steep but short ascent in less than an hour and offers impressive views of the deserted crater landscape and over Lake Shikotsuko. It is also possible to circle the crater in about two hours, but due to poisonous gases it is not allowed to enter the crater. The trailhead is difficult to access without a rental car.

At the northern shores of the lake stands Marukoma Onsen, a ryokan with unique hot spring baths that are also open to non-staying visitors. The baths are located right along the lake shore and are connected to the lake by small canals, allowing for a certain exchange between the pools' hot water and the lake's cool water. Moreover, their water level changes according to the lake's water level and can be uncharacteristically high for onsen pools outside of winter. The ryokan has also conventional hot spring pools, all of which are gender-segregated.