The world's largest fully steerable radio telescope.

The haunting "Hell House Altar" is one of the few remnants of an abandoned college that has been a magnet for local legends.

This sprawling farm was once a Cold War-era hideaway for the nation's top diplomats.

Despite its lavish ornamentation, and wholesome lifestyle of its devotees, this mountain commune has faced its share of issues.

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

Moonbows over Kentucky.

Granite outcropping that the state's tourism bureau doesn't promote because of its delicate ecosystem.

Mysterious ancient boulder carved with petroglyphs in the mountains of Western North Carolina.

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

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

A slab of sandstone covered with mysterious 1,000-year-old rock carvings from a vanished North American culture.

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

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

These strange large stones served as a campsite and lookout post for generations of Native Americans.

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

A sculptor's dream castle turned fantastical ruin.

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

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

A wonderful display of arts and crafts handmade by local artisans in the Southern Appalachians.

This colorful West Virginia cowboy greets passersby with a glassy stare.

Gnarled canopies of pink and purple wildflowers arch over the trail to the summit.

Beautiful waterfalls grace a canyon visibly torn by a violent tornado.

Art museum based around the collections accumulated over 58 years by one eccentric thrift store owner.

The farming museum contains an extensive taxidermy collection, including the world's largest stuffed horse.