A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

A man-made island in scenic San Francisco Bay.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

Disney World's very first waterpark is now an abandoned ruin being reclaimed by the swamp.

Once featuring over 60 miniature replicas of famous Chinese locations, the Splendid China theme park was completely abandoned and is now mostly rubble.

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

"We Seceded Where Others Failed."

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world’s largest coastal brick fortresses.

This huge pile of volcanic boulders hides a stunning network of secret grottoes.

These eclectic homes nestled into the cliffs of a Caribbean island were built entirely from scavenged materials.

Starting with nothing more than discarded conch shells, one man has built an island/bar that would make Jimmy Buffet jealous.

What was meant to be a temporary exhibit is now a permanent fixture at the St. Louis Zoo filled with beautiful birds.

This is not your typical jungle gym.

Less a museum than a bizarre fantasy world created by artists and engineers.

This 17th-century street hidden beneath Edinburgh was once a breeding ground for the black death.

The Metropolitan Police refurbished the blue box (perhaps not coincidentally) the same year "Doctor Who" returned to TV screens.

Catacombs turned marketplace.

Pop culture has helped to keep this iconic British building from being destroyed.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

A hands-off space for graffiti artists to hone and display their skills.

This luxury shopping lane has been protected by its own tiny police force for over a century.

Famously misunderstood wonder of the ancient world