Furen Lake is located at the base of the Nemuro Peninsula and is a brackish lake mixed with seawater with a circumference of approximately 96 km. Located within the Notsuke Kazaren Provincial Natural Park, it offers a varied natural environment with vast marshlands, forests, and sand dunes.

Not only is it the largest swan landing site in Japan, but together with Shunkunitai, it is known throughout the country as a leading bird paradise, where more than half of the 330 species of wild birds that can be seen in Japan can be observed.

Swans visit from early October to late December, when Lake Furen is frozen over. The following year, swans visit from mid-March to early May.