This house's itty bitty size means no humans allowed.

This stunning natural double arch, the largest in the Alps, went undiscovered until 2005.

Most-visited and most-photographed slot canyon in the American Southwest.

Mosaics, storks, and brothels—this ancient city has it all.

This 140-year-old beacon off the Florida Keys marks the wreck of a Navy ship that once roamed the Caribbean hunting pirates.

The world's only underwater laboratory where "aquanauts" study oceanic life.

An underwater city for the dead.

The fairy tale castle of the "fairy-tale king."

The oldest cemetery in New Orleans, resting peacefully for over 200 years now.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

Famously misunderstood wonder of the ancient world

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

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

A fortified city, home to a remaining population of five families

An abandoned horror film set sits eerily along a highway through Hollywood's "door to the desert."

The remains of a magnificent medieval fortress that was the capital of a vast empire.