Beneath the Yucatan Peninsula's surface in Mexico, a hidden natural wonder stretches out of sight. Sistema Sac Actun, the ...

Despite all those years of exploration, still each year, courageous cave explorers discover new tunnels and rooms underground ...

the sound can be heard anywhere from within the cave system, which covers about 64 acres (260,000 square meters). That makes it the largest musical instrument in the world. We’ll save the ...

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 ...

This Thursday at the Judges Breakfast in Clearlake Kevin Kealey shared some of the folklore surrounding Mt. Konocti, as well as its best kept secret – what could possibly be the worlds ...

two of the top three largest known caves in the world. To get there, a punishing path and 90 percent humidity test even the fittest hiker. A walk for the fortunate few: Only a limited number of ...

For just a few weeks a year, sunbeams shine two hundred metres down through a hole in the cave roof, illumining the underground world. Filming this natural lightshow successfully relied on it ...

“There is so much more to do.” When Howard and Deb first saw these enormous spaces, they felt certain they had discovered the largest cave in the world—and they might be right. There are ...

The Camuy River flows through the third largest cave system in the world — so extensive, in fact, that it underlies parts of three towns: Camuy, Hatillo, and Lares. Accessible via the main ...

Sistema Sac Actun is the world's largest underwater cave at 215 miles, a breathtaking labyrinth of nature and history beneath ...

Discovered in 1999 inside an abandoned mine in Southern Spain, Pulpí Geode is the largest crystal 'cave' of its kind in the world. But what exactly is a geode and how do crystals form inside them?