Introduction to Black Dragon Pond: At the foot of the south cliff of Yangtian Pond, the pond is more than a foot deep and covers an area of 100 square meters. It accumulates water all year round and does not dry up even in severe droughts. The color of the water changes frequently. The book "Shuo Ling" records that there is a black dragon living in the pool. When the dragon is there, the water is black, and when the dragon is gone, the water is clear. The locals call it the Dingmen Water of Huashan Mountain.