Vietnam's Son Doong, the world's largest cave passage, started its life millions of years ago as a crack the width of a piece of hair. Today, adventurers marvel at the surreal caverns in its depths.

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 ...

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 ...

The deepest caves on Earth are still being studied by scientists. They are unique environments created over millions of years ...

Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory. She reports on topics from maths and history to society and animals. Katie has a PhD in maths, ...

Some places on Earth feel like they belong in another world, and a few caves are so unsettling that even explorers hesitate ...

From lava tubes on Mars to ice pockets on Europa, subterranean environments may offer the best chance of finding life—and ...

The Tentative Lists of States Parties are published by the World Heritage Centre at its website and/or in working documents in order to ensure transparency, access to information and to facilitate ...