Puerto Princesa Subterranean River, Philippines 普林塞萨港地下河，菲律宾

Beginning in a crystal clear lagoon at the mouth of a limestone karst cave on the Philippine island of Palawan, the Puerto Princesa Subterranean River is the world's largest underground river. The 8.2-kilometer-long river flows through a cave before escaping into the South China Sea.
普林塞萨港地下河是世界上最大的地下河，它开源于菲律宾巴拉望岛上喀斯特石灰岩山洞口晶莹剔透的泻湖。这条8200米长的河流在流入中国南海前流经一个山洞。