Ōwakudani (大涌谷, lit. “Great Boiling Valley“), and not “Owakidani” as the card’s caption has it, is a volcanic valley with active sulphur vents and hot springs in Hakone. It was created around 3,000 years ago as a result of the explosion of the Hakone volcano.  It’s a popular tourist site for scenic views, volcanic activity, and kuro-tamago (黒卵, lit. “black egg”) — a local specialty of eggs hard-boiled in the hot springs  they turn black and smell slightly sulphuric, and eating one is said to add seven years to your life.  (How fast can we get there?)  Unused old postcard with a longer Japanese caption on the reverse.  Grade: 1