The longest known underwater cave in the world is even longer than we thought. As of the start of this year, cave divers have mapped 524 kilometers (325.6 miles) of a subterranean water 'web' near ...

Mammoth Cave National Park, home to the world’s longest known cave system, stretches for more than 680 kilometres, and counting, into the Earth. What began as a limestone labyrinth has turned out to ...

Every single one of America’s national parks is unique, with a beauty that’s entirely its own. “The park's cave system is the longest in the world, stretching over 426 miles, and offers visitors a ...

Researchers have discovered the remains of an ancient shark deep inside the world's longest cave system. The newly discovered shark, plucked from the walls of Mammoth Cave in Kentucky, lived around ...

The air is cool and damp. The light shining from behind is low and tinted, while a park ranger's hand hovers over a button. Then, a switch clicks. Light floods a chasm in the stone, a chamber called ...

Divers in Mexico's Yucatan Peninsula say they have discovered the world's largest underwater cave. Underwater archaeologists discovered last week that the cave system known as Sac Actun, located near ...

Mammoth Cave, the world's longest known cave system, stretches 426 miles under Kentucky. The cave's limestone began forming 330 million years ago when the region was submerged under an ocean. Visitors ...

Ox Bel Ha, located beneath Mexico’s Yucatán Peninsula, has officially reclaimed its title as the longest underwater cave ...

When the summer sun is blazing, there’s no better way to cool off than by heading underground. Caves offer a naturally air-conditioned escape, along with a chance to explore some of the Earth’s most ...

Mammoth Cave National Park in Kentucky is home to the world’s longest cave system, with over 426 miles of mapped underground passages. While here, visitors can hike the Cedar Sink Trail and explore an ...