Black egg at Owakudani Volcanic Valley - Bildbanksfoto

Legend has it that eating an Owakudani black egg will add seven years to your life. Thus, a popular tourist activity is eating eggs that have been cooked in water heated by the natural heat of the Owakudani Volcanic Valley. The sulfur turns the eggs black and gives them a particular odor, making eating the egg adventurous and memorable for many tourists.