Ōwakudani

thumb|Ōwakudani as seen from the Hakone Ropeway thumb|Ōwakudani in 2017 thumb|Kuro-tamago hard-boiled eggs thumb|Owakudani sculpture 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 — 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.