10 Underground Walks

1. Aktun Chen Eco Park Caves, Yucatán, Mexico


Walk by subterranean rivers (locally called cenotes) and peer through deep, crystal-clear water to the white floors of natural wells. Peace reigns in this surreal world of spectacular rock formations, stalactites, stalagmites, fossils, and fruit bats lying beneath untouched rain forest. Explore by foot or by scuba diving.





2. Mammoth Cave