Noboribetsu Jigokudani, the Hell Valley: the walk, heat and lights

Jigokudani means Hell Valley, and the name fits the view from the deck: a bare, grayish slope streaked with yellow, white steam rising from vents, and the smell of sulfur on the wind. It is the site of a crater 450 m across and 11 hectares in area, created by the volcanic activity of Mount Hiyori.¹ The steam you see is the hot-spring supply of the whole resort made visible.

The numbers show how much water is moving. As much as 10,000 tons of hot spring water of various types gush out of the Jigokudani area every day, and it is supplied to the hotels and inns of the resort below.⁶ Many of the town's baths draw on this one crater, which is why one resort can offer so many kinds of water.

The valley is also young in geological terms. The association says Jigokudani was created by volcanic activity about 10,000 years ago.⁷ Nothing here is staged. The vents, the bubbling pools and the changing colors of the rock are the process still running, which is why it looks different from one visit to the next.

Past the overlook, a wooden path follows the valley floor. Around the middle of the valley is Tessen Pond, a small geyser. It does not spout as much as it used to, but the path lets you look at the river of hot water and stand next to a spring source.⁸ Even without an eruption, the color of the stream and the steam from the rocks are worth a slow look.

Further up is Okunoyu, a grayish-black sulfur spring that gushes from the bottom of a cone-shaped pond. The surface temperature of the pond is as high as 75°C to 85°C.⁵ Keep to the boardwalk and the railings. Water that hot scalds.

Photographers should expect fogged glass. Wipe your lens if you walk near the vents, since steam condenses on it, so carry a dry cloth. Color photos work best when the sky is clear, and the steam shows most on a cool morning.

The valley does not close at dusk. The lights at the Jigokudani Observatory are on until around 11:00 PM, and the area is not locked off, though the association recommends visiting before sunset if you want to see it.⁴ Onibi no Michi, the lit path, is free and open all year from sunset to 21:30.¹¹ At that hour the steam picks up the lights and the valley looks like a stage set.

On set nights the valley hosts demon fireworks. Tickets are 500 yen per adult, with elementary school children and younger free.³⁵ The show starts at 8:00 pm and lasts about 15 minutes, and spectators are limited to 1,000.^36,37 Check the association's calendar for this year's dates, because they differ by month.

Go with a plan. Carry a small torch or phone light for the unlit stretches, wear shoes with grip, and keep to the path. In the dark you cannot judge where the boardwalk ends, and the ground beside it can be hot. If you go alone, tell someone at your hotel where you are headed.