The cave floor was historically used as a natural storage facility for silkworm eggs and tree seeds to delay their hatching until spring.
The cave walls are lined with basaltic lava, which significantly dampens sound and reduces echoes compared to limestone caverns.
The ice pillars are created by dripping water that freezes during winter and early spring; they are largest when temperature fluctuations are greatest.
The cave is part of the extensive volcanic subterranean network located under the Aokigahara Jukai forest.
The name 'Fugaku' is a classical Japanese term for Mount Fuji.
Fugaku Wind Cave is a 201-meter-long lava tube formed by the cooling of basaltic lava flows from the 864 AD eruption of Mount Fuji. The cave maintains an average internal temperature of approximately 3 degrees Celsius throughout the year. It historically functioned as a natural refrigerator for storing silkworm eggs and seeds during the Edo period. Visitors traverse a subterranean path featuring naturally occurring ice pillars that typically peak in size during the winter and spring months. The tunnel walls exhibit a high sound-absorbing property due to the porous nature of the volcanic basalt, resulting in low echo levels. The site is situated within the Aokigahara Jukai forest, a densely wooded area characterized by uneven, lava-formed terrain. The cavern's geological formation includes 'lava stalactites' and 'lava benches' created by flowing molten rock. It remains one of the most accessible and stable lava tubes within the Fuji Five Lakes region.
The illuminated ice pillar section at the deepest point of the cave.
Bring a light jacket, as the internal temperature remains near freezing regardless of external weather conditions.
Wear shoes with good grip, as the wooden walkways and stone steps can be slippery due to condensation and ice melt.
Check the official website before travel, as the cave may close temporarily during severe weather or heavy snow.
Do not wander off the marked paths, as the surrounding Aokigahara forest floor is jagged, uneven, and dense.
Open year-round, but may close during hazardous winter weather conditions or for periodic safety inspections.
Maintain silence to avoid disturbing the cave's sensitive environment; refrain from touching the cave walls or ice formations.
