• Sightseeing Cruise

Hunting for Algae Spheres in a Volcanic Crater

Learn about the underwater secrets of Lake Akan

Lake Akan is the only place in the world where algae form large spherical colonies, known locally as marimo. But why is this crystal-clear crater lake the only spot where these green balls grow naturally? Join this tour and let a local guide help you unlock this mystery. After learning about marimo basics, head out across Lake Akan by boat. This journey takes you to Churi Island, home to the Marimo Exhibition and Observation Center. After you return to the shore, venture into the virgin forests that surround the lake.


When May 1 – November 30
How Long 3 hours
Cost Adults (13 years old and over) 4,000 yen, children (4 years old and over) 2,800 yen. Multilingual display and audio guide available
Contact Akan Tourism Association & Community Development Organization
Link en.kushiro-lakeakan.com