Introduction to the virgin forest: The virgin forest covers an area of ​​more than 2,000 hectares and is located at the end of Rize Valley. This natural green barrier exudes a deep and ancient mysterious atmosphere. The fluffy green land of the forest is covered with lichens. Lichens are natural environmental detectors. As long as there is a little bit of harmful substances in the air, lichens cannot survive. The appearance of lichens shows that the air quality in Jiuzhaigou is very pure.