Ice Cave (Lava Tunnel)
It
is an extraordinary sight caused by lava tunnel collapse. The entrance is in half-moon
shaped, about 8 m high and 20 m wide. In most areas of
Jingpohu region, there exists a permafrost (a layer of soil or rock remaining
frozen for the whole year) in the several meters beneath the earth surface due
to the long and cold winter, so this underground lava tunnel is also frozen all
year round. The air circulation in the tunnel is not smooth, thus the
ice will never melt all the year round, and the
visitors feel more chilling in summer than any other
time.