On the sheer limestone face of the Rock of Gibraltar, a hidden chamber has been sealed off from the outside world for roughly 40,000 years. When archaeologists finally broke through the sand and rock ...
Here’s how to plan a trip to Mammoth Cave National Park.
Tourists swim in a cenote, or flooded cave, outside Playa del Carmen, Mexico. The Yucatan Peninsula is dotted with thousands of these interconnected limestone caves, which are fed by a ...