Hokkaido's largest hot spring resort town, Noboribetsu draws its water directly from Jigokudani ("Hell Valley"), a volcanic crater just above the town where sulfurous steam and spring water constantly bubble up. A single source area here yields nine to eleven distinct spring types — sulfur, saline, iron and more — giving Noboribetsu one of Japan's widest ranges of mineral hot spring compositions in one place. The Jigokudani boardwalk lets visitors get close to bubbling thermal pools and steam vents, and evening events sometimes light the valley in red. Nearby, the Oyunuma River lets you wade through a natural stream fed by hot spring runoff for a foot-soak.
