With its villages of indigenous Ainu people, ancient forests, and incredible natural phenomena, Akan-Mashu is a national park of significant cultural importance.
It's best known for its three volcanic lakes. Lake Akan is famous for its marimo, a rare algae that forms into ball shapes, which are displayed in the Akankohan Eco-museum Center all year round. You can even take part in a guided tour to hunt for these algae spheres. Its other volcanic lakes are the vast Lake Kussharo, the largest caldera lake in Japan, and Lake Mashu, said to have some of the clearest waters in the world.
This less-explored corner of Japan presents an excellent chance to explore an active volcano, Mt. Iozan.