The most interesting thing about Shuanglongdong is between the outer hole and the inner hole. There is a huge rock covering the first-class clear spring. The waterway is wide and the rock bottom is only about a foot away from the water surface. Lying straight at the bottom of the boat, the boat is drawn through the surface of the rock, and when it is worn in the middle of the rock, it is dark. Into the two or three feet, but suddenly and cheerful, known as the spectacle. The inner hole is about 2,000 square meters and the cave is deep. On the shore of the boat, looking up, there is a cyan stalactite ridge from the northeast of the cave, and a yellow stalactite dive from the northwest. People call it "double dragon". The dragon is clearly distinguishable and vivid. .