Furen-ko Wetland spreads over the downstream area of the Furen River, which flows into Lake Furen, a brackish lake with a circumference of 96 km in the border of Bekkai Town and Nemuro City. Lake Furen was formed when the water flow was dammed by a huge sandbar created by the coastal current in Nemuro Bay. As it is directly connected to Nemuro Bay, a vast wetland was formed at the mouth of the Furen River.

Furen-ko Wetland is a wildfowl paradise, where nearly 300 species of wild birds can be observed. Those include rare species such as White-tailed eagles, Steller's Sea Eagle, Blakiston's Fish Owl, and red-crowned cranes. Also, migratory birds such as Whooper swans, bean goose and snipes come and stay here for a short period or winter here. Lake Furen and Furen-ko Wetland together with Shunkunitai were designated as a Ramsar Site as Furen-ko and Shunkunitai in 2005.