In 1999, the Underground River Park was listed as the World Natural Heritage Site. It should not be exciting to visit such places many times, but this underground river cave is too grand. In order to protect the environment, without lighting, it is a dark world to enter. The lovely bats are flying and flying. Sometimes strange sounds come out in the water. It feels like a fairy tale world. The canoe is paddling gently, occasionally arousing a splash of water. The strange smell in the cave is bestowed by the bats. Most visitors will return only 1.5 kilometers into the underground river, while the whole underground river is more than 8 kilometers, and then go forward, some places need to dive to pass.