Lake Shikotsu-ko支笏湖（しこつこ）

Japan's northernmost ice-free lake, popular for fishing and boating, remains unfrozen even throughout Hokkaido's harsh winter.

Lake Shikotsu-ko is located in southwestern Hokkaido, west of the city of Chitose. It is a crater lake that was formed over 30,000 years ago by volcanic activity, and it has a maximum depth of 360 meters, making it the second deepest lake in Japan. It is an oligotrophic lake with visibility to a depth of 25 meters, and does not freeze in most winters. This makes it the most northerly lake in Japan that does not freeze over.

The eastern lakeshore near the mouth of the Chitose-gawa River is the center for tourists, and has hotels and pickup points for pleasure boats. Other facilities include Hokkaido's largest campsite and a wild bird observatory on the southeast shore, and a national campsite on the west shore. On 10-meter-high rock bluff faces that stretch for 500 meters, is a cave, the mouth of which is thickly covered with about 30 varieties of moss, giving it a lustrous, dreamlike beauty.

In summer, people enjoy boating on the lake - on pleasure boat tours, cruisers and motorboats, or they fish for rainbow trout or go scuba diving. In winter, the Chitose-Shikotsuko-Hyobaku-matsuri Festival (ice waterfall festival) features objects made out of ice, which are lit up to produce a fantastic spectacle.