China's biggest ice cave continues to expand

China's biggest ice cave, formed some three million years ago, in the northern Shanxi province continues to accumulate ice.
The cave, in the Luya mountain in Ningwu County, Xinzhou City, is connected with Fenhe River, which is believed to provide water for the cave, said Du Erping with the management office of Luya scenic area.
At an altitude of 2,300 meters, the cave is more than 100 meters deep.
The stunning natural spectacle is the largest ice cave to be discovered so far in China and is believed to date back three million years.
"Some villagers say their great-great-grandfathers had known about the cave," Du said. During World War II, war horses that were killed during fighting were stored in the cave, as the sub-zero temperature ensured the meat would keep and it could be eaten at a later time.

The wooden ladders in the cave are cleaned twice a day, otherwise they would collect layers up layers of ice.

"Because the ice continues to form, the ice cave changes all the time," he said.
Scientists are still researching how the cave formed.
"Such caves are normally found in extremely cold areas such as Antarctica or Siberia, but Luya mountain is at a similar latitude to Lisbon in Portugal," Du said.
Once, as an experiment, a haystack was placed at the bottom of the cave and it disappeared, only to be found the next day in the river.
The cave also has several gaps where wind enters. Workers block them during the day for the sake of tourists, and unblock them at night, Du said.

The cave is open for visitors from April to October each year, when a maximum of 3,000 people are allowed to enter daily.
In the past, villagers used the ice from the cave for medicinal purposes. However, to protect the cave, such behaviour is now banned.