Noboribetsu Jigokudani (Hell Valley) & Oyunuma Geothermal Pond

Category: Active Volcanic Crater & Natural Hot Spring Resort | Location: Noboribetsu Onsencho, Noboribetsu, Hokkaido 059-0551

Noboribetsu Onsen is celebrated as the undisputed sovereign of hot springs in Hokkaido, rightfully crowned the "Department Store of Onsen" because its subterranean plumbing delivers nine distinct chemical thermal water varieties from a single locality. The dramatic volcanic crucible fueling this thermal empire is Jigokudani (*Hell Valley*), a colossal 450-meter-wide volcanic explosion crater spanning eleven hectares formed roughly 20,000 years ago. Across its desolate, sulfur-bleached amphitheater of yellow and rust-colored cliffs, roaring steam vents and bubbling mineral cauldrons discharge an astonishing 10,000 tons of 80°C geothermal water every single day to supply the town’s traditional onsen ryokans. Well-maintained wooden boardwalks navigate through the heart of Jigokudani, leading walkers right up to Tessen Ike, a violently bubbling intermittent thermal spring erupting every few minutes at 80°C. In the evening, the boardwalk is illuminated by rustic wooden lanterns along the "Demon’s Fire Path" (*Onibi no Michi*), casting flickering shadows that evoke Hokkaido’s benevolent onsen ogre guardians (*Yukijin*). Ascending through dense deciduous forests leads to Lake Oyunuma, an eerie volcanic crater lake one kilometer in circumference where boiling black sulfur mud reaches temperatures of 130°C beneath smoking vapors rising against Mount Hiyori. Following the steaming outflow river down through primeval forest trails reveals the Oyunumagawa Natural Footbath (*Tennen Ashiyu*). Here, travelers take off their shoes, sit on rustic wooden logs along the riverbank, and soak their tired feet directly in the warm, 40°C sulfurous riverbed as sunbeams filter through emerald birch leaves. Admission to Jigokudani and the natural forest footbath is entirely free year-round, situated just a 15-minute scenic bus ride on the Donan Bus from JR Noboribetsu Station.