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

Ruins of the elaborate house where the enigmatic costume designer threw glamorous parties for New York's theatrical elite.

As state high-points-by-elevation go this spot is one of the lowest, but for years it was also the hardest to climb.

A virtually untouched "home on the hill" for the flora and fauna of Rhode Island.

A rapidly disappearing glacier filled with extinct grasshoppers, perfectly preserved in the ice.

New fungal and bacterial species call this deadly lake home.

Mining town from the late 1890s, once home to Calamity Jane.

Natural sonic phenomenon comes with a grisly legend of murder and blood.

These ruins of a pre-Columbian cliff village are among the most beautiful and well preserved in New Mexico.

A unique geological area spiked with wind-carved rocks that resemble teepees.

Despite time, colonization, and the brutal New Mexican heat, these Pueblo ruins still stand.

A cave's rare beauty held a cavernous secret hidden underground.

A multi-storied adobe complex has been inhabited for more than a thousand years.

These aggressively sustainable art homes look like something out of 1970's science fiction.

A phenomenal assembly of pueblos in New Mexico is the most complete example of ancient ruins north of the border.

Legends surround this jagged rock formation in the New Mexico desert.

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

Walk the whole Mississippi River!

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

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

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

Enormous lake at the bottom of a unique cave system.