Mount Fuji‘s past eruptions and resulting lava flows have created multiple caves in the Fuji Five Lake region around the mountain’s northern base.
Today, three of these caves have been developed and opened to tourists to be explored without special equipment or guides. Take caution, however, as some of the caves have passages with low ceilings and steep steps that can be slippery when wet.
Narusawa Ice Cave, 鳴沢氷穴
Even during the summer, the temperature in the Ice Cave usually stays below freezing. Consequently the cave has been used since the early 1900s to store ice for use around the year. The circular walk through this cave is not very long, but contains passages with low ceilings and slippery stairs.
The Narusawa Hyoketsu Ice Cave is located at the east entrance to the Aokigahara Jukai “sea of trees” forest, and is regarded as one of the tourist spots within the Fuji Five Lakes area that can be visited throughout the year.
Over 1150 years ago, during year 6 of the Jogan era (864 a.d.), Nagaoyama, a flank volcano of Mt. Fuji erupted. The red hot lava flow (Aokigahara Maruo) descended between ancient parasitic volcanoes, creating this two-tunnel type cave. After being designated by the Ministry of Education as a natural monument in 1929, it was introduced to the world as a geological wonder.
By the way, the tree-type lava bed is said to have the most spiracles in the world.
Gallery
Narusawa Ice Cave - Entrance
Narusawa Ice Cave - View
