This maze-like slot canyon is a unique gem within an already fascinating geological area.

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

This granite rock face is named for the magnificent reflection that occurs when the sun hits it just right.

An early life spent in this "Old Kentucky Home" inspired the writings of North Carolina's most famous novelist.

From golden eagles to peregrine falcons, this rehabilitation and education center is a haven for birds of prey.

This 5-by-6-foot wooden hut is the smallest historic post office in the U.S.

Wander through more than 20,000 square feet filled with an amazing collection of orchids.

This North Carolina store preserves a historic moment in America's movement for racial equality.

This nine-story building can be played like an instrument.

Jule Körner's house full of bizarre architectural details.

A piece of outsider public art accompanied by a strange urban legend.

This bright yellow relic is the final survivor of a short burst of seashell-shaped petrol pumps.

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

A psychological self-portrait in the form of a giant, segmented head.

This woodland architectural installation acts as a camera obscura for the heavens.

These eerie outliers of the lightning bug family glow a mysterious blue color.

This museum pays tribute to the Cherokee leader who created a written language for his people.

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

Knoxville’s architectural icon was the symbol of the 1982 World’s Fair, even catching the googly eye of Bart Simpson.

An abandoned town is hidden in Great Smoky Mountains National Park.

Mile-long cave system near Great Smoky Mountains.

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

The secret city built by the Manhattan Project.

Enormous lake at the bottom of a unique cave system.