【CAUTION! Volcanic gases are hazardous to your health. Do not enter this area if you have asthma, bronchial disease, respiratory disease, heart disease, etc.】 Ōwakudani is a popular tourist spot that attests to the past volcanic activity of Hakone. Actually a crater on Mt. Kamiyama formed by the last volcanic eruption of Hakone around 3,000 years ago, Ōwakudani still actively emits a white “smoke” of sulfuric volcanic fumes. The desolate sight traces back to the time when the place was called “Grand Inferno,” which was later renamed when the Meiji Emperor and Empress visited Hakone in 1873 because people hesitated to invite the Emperor and Empress to a place with such a name. It almost seems a shame to have lost such an evocative name. Now, a tourist center has been established with souvenir stores and a restaurant/café. “Kuro-tamago” (black eggs) have gained popularity as a local specialty of eggs hard-boiled in the hot springs.


Prepare to be mesmerized by billowing volcanic steam over the active volcano, Owakudani, the Great Boiling Valley. Created around 3,000 years ago after the last eruption from the Hakone volcano, today you’ll find the crater-valley to be a popular tourist site, despite the ominous and evocative name. 

The volcanic valley is still alive today with active sulfur vents and hot springs. Before the 1870s the valley was called the “Grand Inferno” or “Great Hell” thanks to the streams of white sulfuric smoke reaching toward the sky. But when the Meiji Emperor and Empress visited Hakone in 1873 people hesitated to invite the two esteemed guests to a place with such a dark name.

Marvel at the view from the Hakone Ropeway, 130 m above the valley bottom. Sulfur and water vapor are spouted out at about 100°C, as a result the rocks have become clay, trees die, plants struggle to grow, and the mountain’s crust is visible for all to see. All of this together creates an image of hell that even prompted famed Japanese Buddhist monk, Kūkai, to offer a prayer to Bodhisattva at the sight. At sunset, the sunlight from Lake Ashi glitters off the waters to offer a beautiful sight one might not expect next to the nightmarish landscape.

At the top of the observation deck overlooking Owakudani you might even spot the majestic Mount Fuji on a fine day, this being one of the best spots to see it from.

While here, be sure to try the legendary kuro-tamago—hot spring hard-boiled eggs with shells turned black by the iron sulfide in the volcanic waters. These treats are only available at Owakudani. Eating just one is said to add seven years to your life, but don’t worry, they’re delicious. Another tasty treat is egg-flavored soft-serve ice cream, for the adventurous of stomach. Or how about some specialty Japanese curry, made with pork from the base of Hakone. 

Wander down a short 10-minute walking trail leading through the volcanic area past steam vents and bubbling pools. More rugged hikers might try their feet at the 2-hour hike down to Lake Ashi, but be warned—it can be rocky, slippery, and even windy. Proper hiking and rain gear is recommended. This more difficult path leads down a mountain path and along the lakeshore, until it ends at Kojiri. From there the path reconvenes with the Hakone Ropeway back to Owakudani.

Access Owakudani by the Hakone Ropeway from Owakudani Station, or by bus. Although it is advised that people with asthma, bronchitis, heart disease, pacemakers, and pregnant women not enter the valley due to high volcanic activity. The volcanic gas concentration and temperature are constantly measured at the Hakone Ropeway stations to ensure the safety of guests and the site may be temporarily closed due to high levels of gas or volcanic activity.

Travel tip

This spooky, sulphury, power spot in Hakone is a must visit. Be sure to check out the black eggs – it is said that eating just one will add 7 years to your life.

Detailed information


1251 Sengokuhara Hakone Town, Ashigarashimo District, Kanagawa

Phone Number


Business Hours



Contact before visit (open always)


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