Huanglong Cave is a natural rock cave with an altitude of 1,056 meters. During the Ming Dynasty, the state established a "national ban" prohibiting the felling of trees on Wudang Mountain. Over the course of several hundred years, this place has been filled with towering ancient trees and shady forests that block out the sun. Xie Bingpu, a scholar of the Qing Dynasty, praised in his poem: "Ancient trees tower to the sky, known as the Seven stars; beside them, clear chimes Pierce the blue sky." Inviting the Five elders to talk about the mysteries, I'm afraid a yellow dragon will come out of its cave to listen. During the Ming Dynasty, Taoist priests from Wudang developed an effective medicine for treating eye diseases here, which was called Huanglong Cave Eye Medicine. The Taoists also took advantage of this magical place to generate income. They connected a rope to the pavilion below the Huanglong Cave, with a small basket tied to the rope. If people wanted to buy eye drops, they just needed to put the money in the basket and pull the bell. Then someone from the cave would pull the small basket up and put the eye drops in it to send down. This way of purchasing lasted for a long time, and thus Wudang Mountain came up with a well-known riddle: The eye medicine of Huanglong Cave - Two never meet.