Explore
Mount Fuji's 864 CE eruption created a vast network of underground lava tubes beneath Aokigahara.
These caverns sit below the primeval forest floor and stay near freezing year-round, averaging 3 degrees Celsius. You can enter the three main caves by paying roughly 350 yen at each entrance.
Dress warmly and wear sturdy shoes with non-slip soles. The cave floors consist of jagged, wet volcanic rock that requires careful navigation.
20-30 minutes201 meters long
This 201-meter-long horizontal lava tube historically served as a natural refrigerator. You will find glowing moss colonies and ice formations inside. Look out for the glowing silkworm cocoons and seeds that were once stored here.
20-30 minutesLow ceilings
This 153-meter-long circular cave descends 21 meters below ground. It is famous for ice pillars that remain frozen even in summer. The ceiling is quite low in places, so prepare to crouch or bend double.
30-40 minutesLargest cave
At over 350 meters long, this is the largest of the three main caves. It is named for the protected bat colony living in its depths. The bat colony lives in an inaccessible area, but the complex lava tunnels remain open to explore.
