If drivers cross the rumble strip on this stretch of Route 66 at just the right speed it plays "America the Beautiful."

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

A clear blue swimming hole with hidden caves, still unexplored.

A collection of massive stacked rocks in Texas includes a snarky note on the benefits of modern technology.

Two massive and unstable sinkholes are yearning to unite, and their consummation could be catastrophic.

Over 100 million years ago, beach-bound dinosaurs left permanent marks on San Antonio's landscape.

Tracks near this Texas nature site were once thought to support the Creationist belief that man and dino coexisted.

This former Texas landfill is flush with 300 million-year-old fossils, all fit for the taking.

Decaying military base deactivated in the 70s is now visited by urban explorers and military enthusiasts.

The only international border marker within the United States.

A National Historic Landmark with a scenic clock tower and park filled with deer and peacocks, plus a military museum.

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

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

There is an unmarked red button hidden over Houston's Buffalo Bayou that is just begging to pushed...

Visitors can walk over the largest concentration of Columbian mammoths to have died from one event.

An abandoned quicksilver mining town surrounded by the Big Bend parks.

Mysterious glowing orbs float through the desert night.

Twice a year, visitors can tour the desolate site that birthed the Atomic Age.

In the middle of a desert subdivision, there is supposedly an impact crater site from Kcymaerxthaereal times.

A half-acre utopia in the New Mexico desert features a graveyard, a game of horseshoes, a library, and a mailbox.

Hunt for buried treasure in Nova Scotia.

The profile of one ill-fated deacon was emblazoned forever on this church window during the Halifax explosion.

The legend of a local monster still haunts this small town.

The only diamond mine in the world where you can keep what you find.