Beneath the idyllic resort towns of Mexico's Yucatan Peninsula, daring explorers have uncovered a hidden world of grand chambers and twisting tunnels. The Ox Bel Ha, Mayan for 'Three Paths of Water', ...

Bushman's Hole may seem unassuming on the surface, but this cave in South Africa's Kalahari is one of the world's deepest freshwater cave systems, attracting seasoned cave divers from around the globe ...