GREAT BOILING VALLEY
Great Boiling Valley Hakone is an active volcanic valley. The Great Boiling Valley (Owakudani) is famous for its black boiled eggs - Kurotamago.
Owakudani, also called Jigokudani ("the Valley of Hell"), is a volcanic valley with active sulphur and hot springs in Hakone. Black egg, called Kuro-Tamago in Japanese, is a local specialty, which is a hard-boiled egg in this hot spring. The boiled egg turn black and smell slightly sulphuric. It is said that consuming the egg is to increase longevity. Eating one is said to add seven years to your life!