Jukai trekking at Mt. FUJI
Jukai, a deep forest
There is a deep forest around Mt. Fuji, called Jukai. You will feel the power of nature walking through many trekking courses. The ground is a lava bed and the topsoil is only 10 centimeters, so roots of trees go horizontally. Therefore there are many fallen trees.
The nearest station is Kawaguchiko of Fujikyu Railway, 2 hours from Shinjuku, Tokyo. Buses are available from Kawaguchiko.
Caves made by lava - Fugaku Fuketsu (wind cave)
In Jukai, there are same caves made by lava of Mt. Fuji. Because the lava of Mt. Fuji was very smooth and run fast, these caves were the paths of lava. Fugaku Fuketsu is horizontal and is 201 meters long. Ice still exists in Summer.
Caves made by lava - Narusawa Hyoketsu (ice cave)
The ices in Narusawa Hyoketsu never melt throughout the year. The cave is 153 meters long. The temperature in the cave is stable at about 0°C. You can walk in Jukai between the two caves (maybe less than 1 kilometer).