Kuro-Tamago - the black eggs of the active volcanic valley Owakudani, are boiled in spring water containing sulfur and iron. Smells like sulfur, tastes like usual eggs. Eat it with a dash of salt and it's pretty damn good watching the world burn around you. Sold at 5 in a bag for ¥500, these eggs are said to increase longevity but probably not if I eat them all at one go😂