Owakudani

"A fun random thing to do while you're in Hakone is to take the ropeway up to Owakudani and try their geothermal heated eggs. The minerals turn the shell black, but really it tastes like a naturally salty hard boiled egg. The adventure and views of the geothermal vents make it worth a stop! Beware: will stink like sulfer but thats a given with any naturally heated vent"

"Get off the ropeway in Owakudani (if you don’t mind the sulfur smell!) to see the steam pouring out of vents all along the valley. Most importantly, buy one of the black eggs which gets its colour from the sulfur and iron in the natural spring water in which the eggs are boiled. Eating a boiled egg from Owakudani is said to add 5 years to your life!"