Akan-Mashu

Akan-Mashu occupies the interior of eastern Hokkaido and was declared in 1934, within the first group of Japanese national parks. It was called Akan National Park for more than eight decades and changed its name in 2017, on fully incorporating the Mashu-Kussharo area into its designation.

It is a landscape built by volcanism. Three great calderas hold its characteristic lakes: Akan, a crater lake some 26 kilometres around, hemmed in between active volcanoes; Mashu, famous for the exceptional clarity of its water and for the fog that covers it much of the year; and Kussharo, the largest of the three, with hot springs rising on its own shore that keep stretches free of ice in winter. Around them stand active volcanoes such as Meakan and Io, with fumaroles and sulphur fields, and the whole is covered by boreal forest of spruce and fir with patches of deciduous woodland.

Lake Akan holds a phenomenon that has given it worldwide fame: the marimo, spherical colonies of green alga that grow slowly until they reach the size of a ball and that are preserved here in one of the most important populations on the planet, protected as a Special Natural Monument. The park is also one of the centres of Ainu culture, the indigenous people of Hokkaido: on the shore of Akan is the Akan Ainu Kotan, a community where craft, dance and language are kept alive, and the relationship of the Ainu with these lakes and forests forms part of the story of the place. The wildlife includes Hokkaido sika deer, brown bear, red fox and birds such as Steller's sea eagle in winter.