Ice, Wind and Bat Caves of Mount Fuji

The iconic shape of Mount Fuji dominates the scenery from miles around, but the mountain’s influence also extends deep beneath the surface of the ground. Its past volcanic eruptions have formed a number of lava caves around the Fuji Five Lakes area in Yamanashi Prefecture. Three of them are open to the public to explore: the Bat Cave, Ice Cave and Wind Cave.

All three caves are located in Aokigahara, a forest growing on top of a layer of lava that was the result of a major eruption of Mount Fuji in 864 – the same eruption that formed the caves.

Aokigahara is also known as Jukai – the “Sea of Trees” – because of its thick foliage and surreal, undulating forest floor. The forest also has the more sinister nickname of “suicide forest” because of a history of people who have chosen to end their lives there. Still, it’s a very somber and beautiful area. A short hiking trail runs through Aokigahara and connects the caves with one another.

Saiko Bat Cave

Saiko Bat Cave takes its name from the nearby Lake Saiko and the cave’s winged inhabitants. At over 350 meters long, it’s the largest cave of the three.

Inside, the bat colony lives in a protected area at the back of the cave which visitors can’t access, so you’re unlikely to see any as you make your way around. However, it’s still fun to explore the many different chambers and pathways of the cave, several of which are so low that you’ll have to bend over double to reach the other side!

Narusawa Hyoketsu Ice Cave

As the name implies, the Ice Cave was originally used as a location to store ice during the early 1900s, before the invention of refrigerators. Today the paths are still lined with huge blocks of ice, even in the summer. The 150-meter circular route descends 21 meters beneath low ceilings and down slippery steps. Mind your head as you squeeze through the lava tunnels and keep hold of the handrails when climbing the stairs!

Fugaku Wind Cave

In the past, this cave was used as a natural storage area for seeds and cocoons thanks to its year-round temperature of about 3 degrees. Visitors can see these storage facilities, as well as a lava shelf and pillars of ice during the easy 15-minute walk. The 201-meter length is easy to navigate, as it’s not very steep and the cave roof is not as low as the other two.

All three caves can be explored without the need for a guide or special equipment. Helmets are provided at the entrances, and wearing these is strongly advised, particularly if you’re tall. Appropriate shoes are also a necessity, as many of the passageways are steep and slippery.