Introduction to Xishen Cave: Climb the second step of Huanglong and you will see an outlet of the ancient glacier - Xishen Cave. The cave is located at the bottom of a 40-meter-wide travertine wall. The cave is about 1 meter high and 1.5 meters wide. The 1 meter into the cave is covered with light yellow and milky white stalactites. The mouth of the cave is filled with mist and waterfalls are like curtains. Legend has it that it is a place where immortals purify themselves.