The Hranicka Abyss is at least 1,325 feet deep, and likely goes down further. — -- A team of explorers believe they have discovered the deepest known underwater cavern the world in eastern Czech ...

An excellent diving site, this incredible duo of caves is a favorite of both tourists and locals alike. The two caves—known as Cenote Dos Ojos—were created by two 70-foot sinkholes connected by a ...

The origin story of Hells Canyon, North America's deepest river gorge, has long been unclear to scientists. But new research estimates it formed about 2.1 million years ago when a dramatic flood event ...

For centuries, humans have lived underground. Today, that ancient practice is under dire threat—even as cave life makes more sense than ever. Gabriele Gouellain waits in the kitchen of her ...