Researchers have found an ancient shark fossil in Kentucky’s Mammoth Cave, offering new insight into prehistoric marine ecosystems.

1. Mammoth Cave – Kentucky Established as a national park in 1941 and honored as a UNESCO World Heritage Site in 1981, Mammoth Cave boasts the longest known cave system in the world.

More: Forest Service seeks 20-year block on oil and gas in cave system They can also be sent via mail to 333 Broadway Blvd. SE, Albuquerque, New Mexico, 87102.

Topline Mark Dickey, an American cave specialist who fell ill with severe gastric pain while exploring a cave system in Turkey last week, is the subject of an extensive rescue operation attempting ...

Cave rescuers have made significant progress in their attempt to save American explorer Mark Dickey, who got stuck more than 3,000 feet underground when he became seriously ill during a cave ...