Sansan-no-yu
サンサンの湯42°57′ N 140°30′ EDay use¥600
Iwanai's local bathhouse pours a hot, cloudy, gold salt spring straight from the source for ¥600.
Photo Wakimasa · Wikimedia Commons · CC BY-SA 3.0 and others, credited in the gallery
Know before you bathe
A plain local bathhouse used daily by residents; follow the regulars' lead on rinsing before you get in and keep voices low.
Getting there
In the Maruyama resort area above Iwanai town, 5–10 minutes by car from the centre and close to the Iwanai Resort base.
After a day of cat-skiing at Iwanai Resort, Sansan-no-yu is the cheap, hot answer. The town built it as a bathhouse for residents when the Maruyama springs opened in 1978, and it still works as the neighbourhood sento of a fishing port on the Sea of Japan.
It runs the heavier of Iwanai's two springs. This is strong salt water of sea-water origin, cloudy and gold, and it reaches the tub at 42 to 47°C with nothing added. The town's name for it is atamari-no-yu, which means the warming water. Sink in to your shoulders and you'll keep sweating long after you've dressed.
Drive up to the Maruyama lookout for the view over the town to the Shakotan peninsula, then go down to the harbour for dinner. For a softer second soak, Iwanai Kogen Hotel sells day entry for ¥1,000 to its clear bicarbonate spring.
Quick answers about Sansan-no-yuよくある質問
Can you visit Sansan-no-yu without staying the night?
Yes. Sansan-no-yu sells day entry at ¥600 (2026).
What are the opening hours of Sansan-no-yu?
Sansan-no-yu: 9:00–21:00 (last entry 20:30 on weekends and holidays). Irregular closures.
How much does Sansan-no-yu cost?
Prices at Sansan-no-yu start at ¥600 (2026).
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