Lake Kussharo & Mt. Io
In Japanese: 屈斜路湖・硫黄山
Lake Kussharo, 57 km around, is Japan's largest caldera lake. Nearby Mt. Io (Atosanupuri) steams from more than 1,500 vents, and a 5-minute walk from the rest house takes you right up to them.
Akan-Mashu National Park
Nearby
- Lake Mashu ≈ 25 min by car
- Kaminoko-ike Pond ≈ 30 min by car
- Bihoro Pass ≈ 40 min by car
- Lake Akan Onsen ≈ 1 h 15 min by car
Travel times are rough estimates by car.
- Getting there
- About 5 min by car from JR Kawayu-Onsen Sta. to Mt. Io, and about 15 min to Sunayu on Lake Kussharo
Easier with a tour or car - Fee
- Free (Mt. Io car park ¥500 May–Oct, also valid at Lake Mashu Observatory No. 1 the same day)
- Good to know
- Mt. Io MOKMOK Base (rest house) 8:30–17:00, open daily. Atosanupuri is an active volcano at alert level 1
- Time needed
- 2 h
Checked against the official Japanese website on 2026-10-15. Report outdated info