Jigokudani, or “Hell Valley” in English, is a 24-acre smoking crater of geothermal activity, created by a volcanic eruption 20,000 years ago. Steam vents, geysers, and boiling lakes abound in this park that can usually be smelled before it is seen.
Jigokudani is a spectacular, appropriately named valley just above the town of Noboribetsu Onsen, which displays hot steam vents, sulfurous streams, and other volcanic activity. It is the main source of Noboribetsu’s hot spring waters.
From the valley, there are attractive walking trails through the wooded hills above Noboribetsu. If you follow them for about 20 to 30 minutes, you will get to Oyunuma, a sulfurous pond with a surface temperature of 50 degrees Celsius, and a smaller, even hotter, mud pond nearby.
Rusty mountain vistas surround fiery black sulfur mud ponds and hot rivers that flow down to feed the baths in the nearby well-frequented resort town of Noboribetsu. The formal spas of Noboribetsu date back to the 19th century, and were used as hospitals where wounded soldiers recovered after the Russo-Japanese War. Today the town is known as a sort of hot spring supermarket, boasting dozens of baths with many different kinds of mineral thermal waters.
The springs, geysers, hissing valleys, and baths are watched over by numerous yukijin statues, demons who bid visitors welcome and intercede in the underworld to secure good fortune for humans. Noboribetsu boasts a Shinto shrine dedicated to Enma, the King of Hell, and features a Festival of Hell in August that includes regular Demon’s Firework shows.
Jigokudani itself can be explored via an 8-kilometer network of boardwalks that run through the park that gives visitors access to foot baths in warm volcanic rivers, as well as views of ancient forests and snow-capped peaks within a surprisingly cozy diabolical landscape.
According to the Internet