An enormous pink granite batholith, long attributed with spiritual powers by the Tonkawa Indians.

A 90-year-old underground water reservoir offers a more industrial kind of tranquility.

A popular swimming hole that hides one of America's most deadly diving spots.

A modernist landscape of water and sci-fi concrete.

An emerald-green grotto just a short trip from Austin.

Hiding behind a grocery store is a spectacular cavern carved as part of an old limestone quarry.

This large cave is a summer home to thousands of bats and has a rich history dating back to prehistoric times.

In one of America’s oldest mountain ranges, a long-awaited section of a scenic highway is now open to the public.

This funicular railway rumbles along for a mile up the nearly vertical face of Chattanooga’s Lookout Mountain.

Labor provided by Great Depression-era programs restored these 25,000 acres in Tennessee.

Mile-long cave system near Great Smoky Mountains.

More than five miles of underground passageways.

Home of an evil witch famous within southern folklore.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

Enormous lake at the bottom of a unique cave system.

The highest point in South Carolina was once owned by an energy company that neglected it but now the state is taking it back.

According to local lore, this narrow passageway through two large rocks was accidentally created by the devil himself.

A dramatically eroding canyon thousands of miles from the desert.

Civil War soldiers, captains of industry, and paupers all interred on historic grounds.

This intricate Hindu temple is the largest of its kind outside of India itself and was constructed like a giant puzzle.

Scattered around Atlanta are little doors with big charm.

A bizarre roadside attraction and the first instance of miniature golf in the world.

This natural wonder drops 16 stories straight down through rare flora and streaming waterfalls.