Ōwakudani
Ōwakudani is a volcanic valley with active sulphur vents and hot springs in Hakone, Kanagawa Prefecture, Japan. It was created around 3,000 years ago, as a result of the explosion of the Hakone volcano.
It is a popular tourist site for its scenic views, volcanic activity, and kuro-tamago — a local variety of hard-boiled eggs that uses the hot springs in their preparation. As a result of them being boiled in the mineral-rich waters of the valley, which contain high levels of sulfur, the egg shells turn black and give off a slightly sulfuric odour; eating one is said to add seven years to your life.
Upon seeing the hellish scenery, when Kōbō Daishi visited Owakudani more than a thousand years ago, he offered prayer to Bodhisattva. The Enmei-jizō in Owakudani is said to have its origin in the prayer.
Access
Access to Ōwakudani is via a funitel, the Hakone Ropeway, or a bus line from Odawara Station, Hakone-Yumoto Station, Kowakidani Station / Kojiri, the Izuhakone Bus. There is a road to a visitor center just below the Kuro-tamago hot springs site.Most visitors used to hike the roughly trail or take the Hakone Ropeway to close to where the eggs are boiled to participate in the ritual egg eating. The funitel offers a vast view of Mount Fuji and the sulphur vents just below the visitor center.
Present day activities surrounding sulphur vents are the result of massive land slides in the past. Construction of concrete barriers and stabilization of the area have been under way for decades.