The Camuy is the third largest underground river in the world and it has been cutting this limestone for a very long time. Explorers have mapped over ten miles of passage, 220 caves and 17 entrances so far, and the guess is that the full system runs to something like 800 caves. The public part is Cueva Clara, a chamber 700 feet long and 215 feet high that you reach by tram, full of formations and bats. The Tres Pueblos sinkhole is 650 feet across with the river 400 feet down at the bottom, and you can look into it from three municipalities at once. Taino people were in here centuries before it was formally found in 1958. Closed by Hurricane Maria, reopened 24 March 2021.
Puerto Rico
See it on the map
