Fugaku Fuketsu Wind Cave
The Fugaku Fuketsu Wind Cave is a subterranean passage beneath the Aokigahara Jukai Forest, just off the Tokai Nature Trail. Apart from the initial steps leading down into the rock, the incline is fairly gentle, and even children can safely walk the length of the 201-meter cave and back in 15 minutes. The ceiling is relatively high, but there are a few places where visitors must watch their heads.
Helpful signposts point out features of geological interest, including “lava shelves” where the surface of the then still-molten wall peeled off from the top and curled down to the bottom like a roll of wallpaper.
The deepest part of the cave, where the temperature is a stable 3°C, has a set of shelves for seeds, grains, and silkworm larvae. Though no longer in use, these shelves served as a natural refrigerator as recently as the mid-twentieth century. In summer, ice stockpiled in the cave was sold to buyers from the capital or used to cool fevers. Storing silkworm larvae in the cave helped make year-round silk production possible: whenever they were removed from the cold, they would assume that spring had come, and set about spinning their cocoons.