Ikenoyu Onsen

Ikenoyu Onsen is a natural outdoor bath located by Lake Kussharo in eastern Hokkaido. The bath has a radius of about 15 meters, besides a small changing space there is not much around the spring.
It is a co-ed bath, and bathers can choose to wear a swimsuit (or not). The waters are about 38 degrees Celsius, making it a comfortable bathing temperature for the summer time.
Since the baths are located right next to Lake Kussharo, wild animals come near the bath for warmth during the winter. Although the bath is too cold to enter during the winter, you can stroll around it and watch the wild animals. The baths are open 24 hours, so you can enter whenever you want to.