Lake Akan, Marimo Algae Balls & Ainu Kotan Cultural Village

Category: Natural Lake & Indigenous Ainu Cultural Heritage | Location: Akancho Akankoonsen, Kushiro, Eastern Hokkaido 085-0467

Spanning thirteen pristine square kilometers within Akan-Mashu National Park in Eastern Hokkaido, Lake Akan (*Akan-ko*) is a volcanic caldera lake cradled between two commanding stratovolcanoes: active steaming Mount Meakan and lush, dormant Mount Oakan. The lake is internationally renowned as the exclusive sanctuary of *Marimo* (*Aegagropila linnaei*)—an extraordinary freshwater green filamentous alga designated a Special National Natural Monument of Japan. Through a delicate interplay of gentle subterranean wave currents and mineral-rich lakebed contours in Churui Bay, these algae threads tumble continuously, forming velvety, perfectly spherical moss balls growing up to 30 centimeters in diameter found nowhere else on the planet. To witness these centuries-old living botanical spheres in their natural aquatic habitat, visitors board the Lake Akan Sightseeing Cruise to Churui Island. The island’s high-tech Marimo Exhibition and Observation Center allows travelers to study colossal live Marimo specimens floating and sinking inside giant viewing aquariums fueled by natural lake currents. During mid-winter, the lake’s surface freezes 70 centimeters thick into *Akan Ice Land*, an open-air snow park hosting ice-hole wakasagi smelt fishing, snowmobiling, and nightly fireworks across the ice. Along the southern lakeshore lies the Lake Akan Ainu Kotan—the largest indigenous Ainu settlement in Hokkaido, home to roughly 120 residents across 30 households. Lined with artisan studios hand-carving cedarwood sculptures (*kibori kuma*), delicate bamboo jaw harps (*mukkuri*), and embroidered textiles bearing sacred ancestral protection spirals, the village preserves vibrant oral traditions. At the dedicated Ainu Theater "Ikor", visitors experience the UNESCO-inscribed Traditional Ainu Dance (*Ainu Koshiki Buyo*), complete with spiritual fire ceremonies honoring the crane deities and contemporary digital performance projections. Lake Akan is located a picturesque 1-hour drive from JR Kushiro Station.