Lake Akan is a caldera lake in Akan-Mashu National Park and one of Hokkaido's most popular tourist destinations. The scenery is magnificent, with Mt. Ouakan rising from the eastern shore, and the lake is beautiful in every season. 4 islands are located on the lake, and it is famous for the spherical "marimo of Lake Akan," a special natural treasure, which grows here and is rare in the world. A hot spring resort area stretches along the southern shore and is crowded with tourists and anglers.