Aokigahara Jukai (sea of trees) spreads out at the foot of Mt. Fuji. Narusawa Hyoketsu Ice Cave is located at the eastern entrance of that and is visited by many tourists throughout the year as one of the touring spots of Fuji Goko/Five Lakes. It is a cave created after lava flowed out from the eruption of Mt. Fuji lateral volcano Mt. Nagao in 864(the 6th year of Jogan era), and is a lava cave with a total length of 153 m.
The name was derived from the fact that the temperature inside is averagely as low as 3 degrees Celsius and is covered with ice all year round. The highlight is the icicles formed by freezing water droplets that have exuded from the ceiling. It will be the largest around April, and depending on the year, a huge icicle with a diameter of 50 cm and a height of 3 m may be seen. Moreover, at the innermost of the cave, there is a cave called "Jigokuana(Hell Cave)" that is connected deep underground, and according to a legend, it is connected to Enoshima.