Narusawa Ice Cave: The lava tube brimming with 10-foot-high ice pillars at the base of Mount Fuji
Rapid facts
Name: Narusawa hyooketsu cellar
Location: Fuji Five Lakes region, Japan
Contact details: 35.475766342241734, 138.6658965143265
Why it’s incredible: The cave was created by Lava from Mont Fuji and now holds giant ice pillars.
The Narusawa ice cave is a lava tube full of ice cubes and ice pillars at the base of Mount Fuji in Japan.
The lava tubes are natural tunnels that form under the flow of solidified lava after a volcanic eruption. The lava hardens faster in the upper layers of a lava flow, where the melted rock comes into contact with fresh air than in the middle layers, where it remains red and fluid. As a result, when a volcano stops bursting, the heart of a lava flow flows while the exterior hardens, leaving an empty duct or a cave.
The Narusawa ice cave is one of the many caves that were formed during a violent eruption of Mount Fuji in AD 864. The eruption took place on the northeast side of the volcano, with lava believing in a new vent called Mount Nagao rather than the crater of the central summit of Mount Fuji.
The eruption lasted 10 days and created the large lava plain which is now covered by the Aokigahara forest, a dense forest also known as the “sea of trees”. The explosion also divided a lake in half, pointing to two of the five Fuji volcanic lakes.
The ice cave is one of the three largest caves in this region, with the fugaku wind cave and the Chauve-Souris du Lac Sai cave (also called the Chauve-Souris du Lac Saiko cave). The Narusawa ice cave measures 490 feet (150 meters) long and up to 12 feet (3.6 m) high, According to Wind Cave & Ice CaveThe company that manages and offers visits to the cave. The average temperature in the cave is only slightly greater than 37 degrees Fahrenheit (3 degrees Celsius) because of its particular geology, which means that all humidity is likely to freeze, especially in winter.
The water flowing from the ceiling of the cave forms stalactites and stalagmites that meet in the middle during the coldest months. The best time to visit the Narusawa ice cave is in winter or early spring, when these ice pillars can reach up to 1.6 feet (0.5 m) thick and 10 feet (3 m) high, depending on Wind Cave & Ice Cave.
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The cave is a tourist attraction, but historically, it was used to keep the seeds and cocoons with fresh silk. People have sculpted rectangular blocks out of ice pillars, which they then stacked to create an ice shop or refrigerator, according to the Wind Cave & Ice cave.
“To avoid the growth of cocoons and to preserve the quality of the seeds and promote the bud, they were stored in a refrigerated environment,” said the company on its website.
The cave also holds the leftovers of old trees, which were overthrown by lava flows during the AD 864 eruption, images on the Show website.
The Narusawa ice cave is only half a thousand (800 m) east of the Fugaku wind cave, which extends much deeper below, has impressive lava formations and houses unusual foam colonies, according to the National Organization for Japan Tourism. There is no echo in the wind cave because the walls of pure basaltic rock absorb sound – and unlike the ice cave, there is no frozen water so that sound waves bounce.
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