# Narusawa Ice Cave > A lava tube formed in the 864 eruption on Fuji's north side, kept at about 3°C so ice lasts all year. The loop inside is short, about 150 m, but it is nearly all damp stairs, with one spot only 91 cm high. Entry is 350 yen. - Prefecture: Yamanashi - Type: Attraction - Address: Narusawa, Yamanashi, Japan - Closed: Open every day. Hours can change with the weather or conditions inside the cave. - Hours note: Opens at 9:00 every day. Closing time changes through the year: 17:00 from March 16 to July 31, 17:30 from August 1 to October 15, 17:00 from October 16 to November 15, 16:30 from November 16 to February 15, 16:00 for the rest of February and 16:30 from March 1 to 15. - Admission: 350 yen - Official site: https://www.mtfuji-cave.com/ The cave opened up in 864, when lava from Nagaoyama, a side vent of Fuji, flowed through the forest that is now Aokigahara and left a hollow tube behind. Cold air sinks into it and stays: the average inside is about 3°C, and ice survives through summer. It is a vertical cave, so the walk is mostly stairs. You go down, bend under a ceiling that drops to 91 cm at its lowest, reach a pool of ice at the bottom and climb out again, 21 m up in one go. The steps are wet and slippery, and the loop of roughly 150 m takes about seven minutes. Bring a layer even in August. Ice pillars grow largest around April, sometimes 3 m tall. The cave has been a national natural monument since 1929, and before refrigerators people stored ice in it. Because of the stairs and low passages, children under 4 or shorter than 100 cm are not let in, and you cannot carry a child on your back or in your arms. Fugaku Wind Cave is about 800 m west, and Lake Shoji, Saiko and Motosuko are further along the same road. ## FAQ ### How much does it cost and how long does it take? 350 yen for adults and 200 yen for elementary school children and younger. The loop inside takes about six to seven minutes, though a queue at the entrance can add more. ### Can small children go in? Not if they are under 4 or shorter than 100 cm, and you may not carry a child on your back or in your arms. The cave is narrow, the ceiling drops to 91 cm and the stairs are slippery. Fugaku Wind Cave nearby is flatter and easier. ### What should I wear? Shoes with grip, since the steps are wet and heels are not safe, and a jacket, because it is about 3°C inside all year. Pets are not allowed in, even in a carrier. --- Source: Narusawa Ice Cave — Japan Voyage