Curious cave that stays a cool 56 degrees all year long.

This Italianate Villa-style castle is pretty to look at, just keep off the private property.

This abandoned prison castle has become an imposing gallery of graffiti art.

The "World's Largest Underground Business Complex," a 55,000,000-square-foot city underneath Missouri.

World's second largest particle accelerator, where nature reveals its secrets.

This railroad overpass is said to be home to a murderous goat-man whose very legend has led to very real deaths.

Origin of the blue-skinned Fugates of eastern Kentucky.

You can climb to the summit of Black Mountain, as long as you sign the waiver.

A recreation of the doomed ocean liner in the middle of the Smoky Mountains.

This boulder stays on its mountain thanks to a huge chain and on the map due to local legend.

The highest point in Virginia can only be reached by passing through ponies and flowers.

This bridge is haunted by the ghost of a distraught mother.

The highest point in North Carolina and the United States east of the Mississippi River, Mount Mitchell is named after argumentative explorer Elisha Mitchell.

Railroad came. People came. Railroad left. Town died.

One street divides a single town that stands in two U.S. states.

Home of an evil witch famous within southern folklore.

This former tuberculosis research hospital endeavored to cure the dreaded disease with fresh air and positive attitudes.

The world's longest known cave system.

All that's left of the quintessential "cabin in the woods."

Moonbows over Kentucky.

Better known as the "Body Farm," this unique research facility has been studying how human bodies break down since the 1980s.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.