Owakudani Valley

Owakudani Valley, used be called Jigokudani (“the Valley of Hell”) via Hakone ropeway. It is volcanic valley, so you could see thermal volcanic pools. You have to eat Kuro-Tamago (black boiling egg) there.

The eggs are cooked in the area’s thermal heat sources. If you eat one, your life is supposed to be extended by 7 more years, so legends say anyway.

So if you eat two of them you should have 14 years more life! Obviously this is just a legend and probably not true.

From:

http://www.go-japanese.com/mount-fuji

http://smartrip.jp/area/hakone/2949.html