Kawayu Onsen (쓒) is a small hot spring town inside Akan Mashu National Park's eastern section. It is located near Iozan (Sulfur Mountain), between Lake Mashu and Lake Kussharo. Kawayu's close proximity to the famous lakes makes it a popular base for visitors to the national park.

Kawayu's onsen water is especially acidic with a pH of 1.4. Visitors to Kawayu, who do not overnight at a ryokan with hot spring baths, can bathe at the some of the ryokan that open their bathing facilities to non-staying guests during the day for typically 500 to 1500 yen. There is also a free public foot bath near the Eco Museum Center.

Kawayu's Eco Museum Center offers general information on Akan Mashu National Park and Kawayu Onsen. Nearby, a pleasant walking path takes visitors though a mossy forested area. This path continues onto Iozan (Sulfur Mountain), 2.5 kilometers away.

Besides convenient location and hot spring waters, Kawayu offers a Sumo Museum, which is dedicated to the town's favourite son and biggest star, Taiho Koki. Taiho was a sumo wrestler who achieved the sport's highest title in 1961 at only 21 years of age. He has long held the record for most tournament victories.

Getting there and around

Kawayu Onsen is a station on the JR Senmo Line, but it is located more than three kilometers outside of the town center. A bus operates between the station and the town center (10 minutes 290 yen one way) and is timed with train departures and arrivals. It is also possible to walk from the station to town via Iozan in about one hour.

How to get to and around Akan Mashu National Park

Hours and Fees

Kawayu Sumo Museum


9:00 to 17:00 (5:30 to 21:00 from June to mid October)


No closing days


420 yen

Kawayu Eco Museum Center


8:00 to 17:00 (April to October)
9:00 to 16:00 (November to March)


Wednesdays except from late July through August (or following day if Wednesday is a public holiday), December 29 to January 3