Owakudani Hot Tub
This is a reservoir high up Hakone, a mountainous region surrounding Mt. Fuji. It's not quite clear in this photo, but this location is roughly 1000 ft above sea level. It was a land of snow, clouds, and steam while we were there, far from the urban sprawl of Tokyo. This reservoir struck me as having the potential to be one hell of a mountain hot tub, but maybe that was just chill-induced wishful thinking. To the right is the takeoff for a skyway type system that takes you all the way down the mountain.