Bad farming practices caused this unnatural natural wonder.

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

An unfinished rail tunnel that has since been used to house cheese and bats.

The sole remaining outpost of a once-thriving South Carolina chain still sells “pic-a-nic” baskets.

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

One of the oldest living oak trees in the Southeast.

In Rickwood Caverns, visitors can travel hundreds of feet underground and see beautiful formations unique to the region.

Since it formed millions of years ago, this cave system has been a sacred burial ground, a Prohibition-era speakeasy, and the center of an amusement park.

A natural history museum with an extensive collection of bird dioramas.

Alabama has a fiberglass Stonehenge. With apologies to Spinal Tap, this one is full-size.

148 feet long and in the middle of a verdant forest.

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

This macabre shop, filled with art, oddities, and taxidermy is hidden in the heart of the French Quarter.

Civil War dumping ground for the bodies of terrorized Union sympathizers.

This beautiful grotto is one of those places where you can't believe you're just outside Austin.

This sacred cavern, 400 feet deep, is home to millions of bats and an ancient burial ground.

A Texas cave network is home to some of the world's most spectacular-looking and bizarrely named mineral formations.

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.

A spring water stream jumps through a walkable "bridge" cavern and a narrow canyon.

A rocky shelter in the desert hides one of the largest concentrations of cave paintings in Mexico.

A sprawling network of century-old subterranean catacombs lies beneath a nondescript suburban home.

This centuries-old mine remained hidden beneath a hotel bar until 2013.