Introduction to key cultural relics protection units: In front of the mountain gate of Xuankong Temple, there is a stone tablet sign of "National Key Cultural Relics Protection Units". There have been two theories about the origin of the Hanging Temple: Buddhist legend says that in ancient times, mountain floods often occurred here and the people in the valley were in dire straits. Therefore, a temple was built hanging on the cliff to suppress monsters. Taoist legends claim that the Northern Wei Dynasty used Mount Hengshan as an important Taoist temple for teaching and practice. According to the Taoist requirement of "not hearing the crowing of cocks and the barking of dogs", the ancient craftsmen built this temple suspended on the cliff.