Enjoy A Cool Summer - 3 Caverns Around Mount Fuji

The symbol of Japan: Mount Fuji. Though the last eruption occurred more than 200 years ago, it would be foolish to forget the fact that Mount Fuji is not just a mountain but an active volcano.

At the base of Mount Fuji are many caverns and grottoes that appeared after these past eruptions. Contrary to what their location might indicate, the insides of these caverns are very cool, a perfect contrast to the harsh summer heat. Let's check out three of the best caverns to beat the summer heat in.

1. Feel the Cool Breezes: Fugakufūketsu

Let's start with a protected national monument, Fugakufūketsu.

First, we head to the densely treed Jukai area, also known as the Sea of Trees, where the entrance to the fūketsu (風穴), or "cave from which cold wind blows" is located. In the distance along the route you can just make out the shapes of small lava shelves and gas vents, which really build up your sense of expectation. Fugakufūketsu is a cavern that was created by the flow of lava from past eruptions, and is referred to as Fugaku Lava Cave in English. The interior of the cavern is a comparatively gentle slope rather than extreme ups and downs.

There is a staircase down as soon as you enter the cavern, and once you have descended, you can really feel the refreshing chill of the air. You can sometimes find icicles within the cave as the average yearly temperature of this spot is about three degrees Celsius or 37 degrees Fahrenheit. It's almost like being in a refrigerator. That isn't too far from the truth - this area was historically used as a cold storage storehouse and now there are displays in place to explain this fascinating history.

The total depth of the cavern is 201 meters and it takes roughly 20 minutes to view the entire cavern.

See Giant Icicles All Year: Narusawa hyōketsu

Up next, let's head to another natural monument - Narusawa hyōketsu. As this cavern is just under 1 kilometer away from Fugakufūketsu, visiting them both to compare is quite interesting.

To say that they are close however, refers solely to their distance. Narusawa hyōketsu is more of a shaft-like cavern, with harsh and sometimes sudden changes in elevation; you must be very careful while walking in here. There are icicles here and there inside, so if you are lightly dressed moreso than chilly, you will definitely feel cold here.

And within this hyōketsu, or "ice cave", you might see ice chunks or even icicles that extend from the ceiling to the floor.

The best time to view this cavern is in the summer as the melted snow run-off in the spring is turned into ice in the summer here. During Japanese summers the average outdoor temperature is about 30 degrees Celsius (86 degrees Fahrenheit), but here within the cavern the average summer temperature is roughly 0 degrees (32 degrees Fahrenheit).

3. A Peaceful Home for Bats?: Kōmori Ana

Located a bit away from Fugakufūketsu and Narusawa hyōketsu, is another cavern found at the base of Mount Fuji, known as Saiko Kōmori Ana or the Saiko Bat Cave.

This spot, moreso than the previous two, is a slightly more active place to have fun. After borrowing a helmet from the reception, you first make you way through the Sea of Trees. With your helmet on walking through the dense forest, you will really start feeling like an explorer. Just up ahead of you Kōmori Ana waits expectantly. As you make your way to the entrance, one of the first things that will catch your eye is the large fence. Rather than keeping a ferocious beast inside, this fence set-up is meant to protect the bats, so you can safely head in.

This cavern is roughly 350 meters in length and is believed to be the biggest of the lava caves surrounding Mount Fuji. There isn't a noticeable difference in temperature between the lava caves and ice caves so throughout the year you can enjoy relatively stable climates within them. With chilly summers and relatively warm winters compared to external temperatures, the caverns are the perfect spot for bats to hibernate in, and where the cave got its present name.

Now, the inner part of the cavern has been established as a bat sanctuary, so while visiting, you might even get the chance to meet some bats yourself. The ceilings of the passageways in the bat cave are low, which makes it a fairly hard place to explore. It's a good idea to wear some comfortable, easy to walk in shoes here; you can borrow a helmet from the reception and get some free assistance from the staff too.

Caves are a Summer Must!

As far as cave exploration goes, many might think these spots to be challenging; however, the caverns we introduced here today are comparatively easy even for absolute beginners. This summer, why not visit the Mount Fuji caverns, where you can feel the coolness of the air as you explore these natural wonders.

Information

Mount Fuji Lava Caverns MAP

Fugakufūketsu
Address: Yamanashi, Minami Tsuru, Fuji Kawaguchiko-machi Nishi, Aokigahara 2068-1
Hours: 9:00-17:00 (depends on the season)
Entrance Fee: 350 yen for adults, 200 yen for children
Phone Number: 0555-85-2300

Narusawa hyōketsu
Address: Yamanashi, Minami Tsurugun Narusawamura 8533
Hours: 9:00-17:00 (depends on the season)
Entrance Fee: 350 yen for adults, 200 yen for children
Phone Number: 0555-85-2301

Saiko Kōmori Ana
Address: Yamanashi, Minami Tsuru, Fuji Kawaguchiko-machi, Saiko 2068
Hours: 9:00-17:00 (closed from December-March for bat hibernation)
Entrance Fee: 300 yen for adults, 150 yen for children & junior high students