Deep inside a labyrinthine cave in southwestern France, ancient humans who lived around 30,000 years ago carved horses, ...

Walking into Fingal's Cave is like walking into the heart of the Earth. Here among the towering basalt columns, the visitor stands inside a lava flow. Magma that swelled up from deep in the Earth ...

Take an otherworldly journey through Hang Son Doong, the world's largest cave located in Vietnam. The cave is more than 500 feet tall, 650 feet wide, and 29,500 feet long. Video courtesy of Ryan ...

The frigid, winter weather has provided the rare opportunity to step inside and explore stunning caves carved under the ice. Melting water from the glacier creates the twisting tunnels as it ...