This quirky hot springs town known to locals as "T or C" was named after a radio show.

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

Natural catch-basin rocks covered in thousands of drawings spanning many millennia.

An old saloon in the West filled with history, and according to some, a few dozen ghosts.

A wild west cemetery in Tombstone, Arizona, provides a window into the Old West.

A living snapshot of a different time in America is preserved and maintained by a community of volunteers.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

Where monkeys run wild and the humans are caged.

Former villa and estate of James Deering developed to preserve native tropical forests.

Eco-friendly island mansion.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

One of the longest water bridges in the world was built over a supposedly haunted swamp in Louisiana.

Launchpad for the US military’s dead mouse operation to battle millions of snakes.

This historical swimming pool near Miami is emptied and refilled each day with naturally filtered water.

This shifting North Carolina sand dune is an odd little desert surrounded by oceanic forest life.

Abandoned Air Force base that has fallen into disrepair.

This fairy tale-themed amusement park is now abandoned, and childhood metaphors abound.

Abandoned Coast Artillery fort now serves as a graffiti canvas and sightseeing vantage point.

This abandoned radar station from the Cold War era now only broadcasts a seriously ominous air of isolation.

A decommissioned Naval base now rents itself out for people who want to blow stuff up.

When this test site was abandoned, they didn't even bother to take the rocket with them.

Rusting, graffiti-covered tanks litter the beach of this island, once used by the U.S. military for target practice.

On this Puerto Rican island, many abandoned naval ammunition bunkers sit open while a few have been padlocked by locals as personal storage.