Introduction to Carp Hanging on the Wall: The boat passes through Shuilian Cave and Yangdi Wharf, and one mile downstream you can see a stone wall about 100 meters long and 30 meters high across the river head. The pattern on the wall forms a tail going upstream. The big carp and a small red carp swimming down the water are like paintings drawn by a magic pen. This is "carp hanging on the wall".