My quest to visit more Texas state parks this year took me up to Longhorn Cavern, located off U.S. 281 near Marble Falls.

Local porters ferry the expedition team’s equipment across an underground river to reach various chambers within the cave system. Author Neil Shea squeezes through a passage to enter a ...

For 16 years, the Buffalo National River has denied explorers access to Arkansas’s longest cave and hundreds of others. Some ...

To enjoy the caves safely and comfortably, wear shoes with nonskid soles and take a jacket. Complete your underground trips with a river trip or a walk on the River Styx Spring Trail. The least ...

The walls of Longhorn Cavern look more like a slot canyon than a typical karst cave. An ancient underground river eroded and sculpted a smooth channel through the limestone and the undulating walls ...

The cave system lies about 70 miles outside of Pittsburgh and is currently owned by a private conservancy, which plans to ...

One of their coolest tours is the "Red River Gorge Underground Cavern Glow," which takes paddlers through an abandoned limestone mine by the glow of multi-color, underwater LED lights.On this tour ...

One of Kentucky's most awe-inspiring attractions is Mammoth Cave National Park, which promises unique above and underground adventures and wows hundreds of thousands of visitors year after year.

is an underground river and collection of caves. The bright turquoise water contrasts with the caramel- and mocha-colored rock formations within the caves, which include stalactites and stalagmites.

which manages the nearly 300-acre Camuy River Cave Park. Highlights of the tour include the largest stalagmite in Puerto Rico, glimpses of the underground river (and maybe some bats), and a 450 ...