Step off the desert trail and into Arizona’s longest cave, where crystal formations and subterranean wonders await.

A narrow gap in Gibraltar’s limestone can open into a question that refuses to stay small: how late did Neanderthals really ...

In a limestone cave beneath the oil fields of southwestern Oklahoma, scientists have uncovered something that should not have survived: a fingernail-sized patch of reptile skin that has remained three ...

Below the Chihuahuan Desert in southeastern New Mexico, lies an extensive system of limestone caves, among them the famed Carlsbad Cavern, home to one of North America’s largest underground chambers.

BENSON, AZ — Just south of Tucson lies one of Arizona’s hidden gems—Kartchner Caverns State Park, an active limestone cave system known for its rare, pristine formations and year-round underground ...

Below the Chihuahuan Desert in southeastern New Mexico, lies an extensive system of limestone caves, among them the famed Carlsbad Cavern, home to one of North America's largest underground chambers.

Arkansas will soon name its stunning limestone cavern complex as a state park, which features glowing formations, underground ...

Chinese astronauts, known as taikonauts, were sent into a large limestone cave system in a remote area of China.

Numerous limestone caves lie along the path of the Yūhigawa River as it flows through the city of Nanjō in southern Okinawa. One of the best known of these is the Valley of Gangala, formed by the ...