Beneath the forests near Mt. Fuji lies a different kind of Japan: icy, narrow, and dark—even in summer. The Narusawa Ice Cave is a lava-formed tunnel where ice remains frozen all year, thanks to its low temperatures and volcanic structure.
Originally used as a natural refrigerator for silkworm cocoons, the cave is now open to the public and makes for a quick, unforgettable stop—especially if you’re traveling around the Fuji Five Lakes area.
→Want to take in these views—and more—without the hassle? A guided tour is a great way to enjoy the whole area.
What is the Narusawa Ice Cave?
The Narusawa Ice Cave is a lava tube, created by Mt. Fuji’s eruption over 1,100 years ago. It stretches about 150 meters, with narrow tunnels, low ceilings, and slippery steps—all naturally cooled to around 3°C (37°F) even in midsummer.
The cave is designated as a Natural Monument of Japan, and helmets are provided at the entrance to protect visitors from bumps in tight sections.
It’s one of the few places in Japan where you can step into a year-round frozen landscape—without hiking or leaving the main tourist route.
I’ve never felt cold like this in summer—it’s like stepping into another world! If you’re traveling near Mt. Fuji, it’s a fun little adventure you won’t forget.
How to Get There
The Narusawa Ice Cave is located in Aokigahara Forest, near Lake Saiko in Yamanashi Prefecture.
From Kawaguchiko Station
• Take the Saiko Sightseeing Bus (Green Line) and get off at Hyoketsu (氷穴) bus stop
• Bus ride: ~25 minutes
• Taxi from Kawaguchiko: ~20 minutes
• Rental bicycle: ~45 minutes (moderate hills)
From Tokyo
• Take the JR Chuo Line from Shinjuku to Otsuki Station
• Transfer to the Fujikyu Railway and ride to Kawaguchiko Station
• From there, follow the above directions
• Total travel time: ~2.5 hours
There’s a parking lot near the cave, and signs are available in English. No reservation is needed.
❓ Q&A – Narusawa Ice Cave
Is Narusawa Ice Cave worth it?
Yes—if you’ve never been inside a lava tube or want to escape the heat, Narusawa Ice Cave is a unique stop. It only takes 15 minutes and gives you a glimpse into Mt. Fuji’s volcanic history—plus, it stays icy even in summer!
How do you get to the ice cave in Narusawa?
Take a bus from Kawaguchiko Station on the Saiko Line—it takes about 25 minutes. Or grab a taxi if you’re short on time. It’s easy to find and clearly marked.
How cold is Narusawa Ice Cave?
Temperatures inside stay around 0–3°C (32–37°F) all year long—even during August. Bring a jacket or hoodie, and wear good shoes. It’s cold, but fun!
Is it safe to go inside?
Yes, but watch your head—some parts are low and narrow. They provide helmets at the entrance, and staff are nearby.
It’s safe for most people, but not ideal for those with knee or back problems.
Visitor Info (as of 2026)
• 📍 Location : Narusawa Village, Yamanashi Prefecture
• 🚉 Nearest Station : Kawaguchiko Station (Fujikyuko Line)
• 🚌 Access :
• Bus from Kawaguchiko Station (Saiko Line): ~25 min
• Taxi: ~20 min
• Rental bicycle: ~45 min (some uphill sections)
• 🕐 Hours : 9:00 AM – 5:00 PM（may vary by season）
• 💴 Admission : ¥350 (adult), ¥200 (child)
• 🛁 Facilities :
• Free parking lot
• Small souvenir shop
• Helmets provided (required)
• Public restrooms nearby
Nearby Spot : Fugaku Wind Cave
About a 20-minute walk from Narusawa Ice Cave, the Fugaku Wind Cave is another lava tube formed by Mt. Fuji’s eruptions.
Unlike the Ice Cave, it’s wider, straighter, and easier to walk through—making it ideal for families or visitors with limited mobility. Inside, you’ll find mossy lava walls and displays showing how the cave was once used to store silkworm cocoons.
Try to go early in the day—there’s less traffic and fewer tour groups. And don’t forget a jacket, even in summer! The cold hits you fast once you step inside.