Introduction

South of Sapporo, Noboribetsu Jigokudani ("Hell Valley") and nearby Lake Toya are two of Hokkaido's most dramatic volcanic landscapes, often visited together on a longer road trip day. We reviewed a recent travel vlog covering both and checked the geology and history behind them.

Jigokudani ("Hell Valley")

The valley is the eroded remains of a volcanic crater formed by an eruption of Mount Kuttara roughly 20,000 years ago, following a larger eruption over 40,000 years ago that originally shaped the mountain. It spans about 450 meters across and 11 hectares, still geothermally active today — bubbling sulfuric hot springs, steam vents, and a strong rotten-egg sulfur smell are all genuine, ongoing volcanic activity, not a preserved historical site. It's easy to understand why the name stuck: this is precisely the kind of landscape that gave rise to the historical belief that only demons could survive here. A wooden boardwalk now lets visitors walk through the valley without difficulty, a modern convenience layered on top of a genuinely ancient and still-active geothermal feature.

A short walk or drive from the main valley, Oyunama Pond is a hot, steaming pool whose white vapor gives it the appearance of a giant cauldron — and nearby, a natural hot spring foot bath along the Oyunama River lets visitors soak tired feet directly in the geothermally heated water, a genuinely relaxing, low-effort way to experience the area's heat without a full onsen visit.

Lake Toya

A further drive brings you to Lake Toya, a caldera lake formed by a major volcanic eruption roughly 110,000 years ago — the eruption caused a massive depression that later filled with water to form the lake. At its center, the Nakajima Islands are uninhabited today but accessible by boat tour. The lake and the nearby active volcano Mount Usu are now part of the Toya-Usu UNESCO Global Geopark, recognizing the area's ongoing geological significance rather than treating it as a purely historical feature.

Practical Tips

• The valley's sulfur smell is genuinely strong — if you're sensitive to it, be prepared, though the boardwalk route doesn't require lingering in any one spot.

• Bring a towel if you plan to use the Oyunama River foot bath — it gets a real crowd, but seating mats are provided, and finding a spot by the water's edge is worth the short wait.

• Time a Lake Toya visit for sunset if your schedule allows — the lake's setting is particularly striking in evening light, based on a recent visitor's account.

Sources and Verification Notes

Jigokudani's volcanic formation timeline (Mount Kuttara, ~20,000 years ago, following a larger eruption ~40,000 years ago) and Lake Toya's 110,000-year-old caldera formation were checked against geological references, confirming the specific figures used in the source material.