From Rausu City, head north on Highway 87, past Seseki Onsen and about 1 km further on, you will find Aidomari Hot Spring in Aidomari, which is famous as a dead end of the road.
It is said that the hot spring was discovered in 1897, and is located at the northeasternmost tip of Japan.

Bathing is available from spring through fall, but depending on the weather and other factors, it may not be possible to enter even during the season.
During the season, huts are built by local residents, but during the rest of the year, the hot springs are completely "open-air.

As with the Seyseki Onsen, it is recommended that you check in advance when, when, and how you can bathe before visiting.