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

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

The studio built by fascists in the hopes of "reviving the film industry" with the occasional propaganda film opportunity thrown in.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

The hallucinogenic center of the ancient world.

Monasteries on rock pillars, once accessible only by frayed ropes.

A surreal statue honoring Prague's favorite literary son.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Macabre astrological automaton clock dating to the late 1400s.

Mysterious meeting place for UFO hunters near Area 51.

The hotel where Martin Luther King Jr. was shot is now a museum dedicated to his work.

Elvis's own personal tropical hideaway.

This Memphis recording studio launched the careers of Jerry Lee Lewis, Johnny Cash, and Elvis Presley.

Every day a troupe of pampered water fowl walk the red carpet to their favorite fountain.

A sign at the end of the Santa Monica Pier marks the traditional end of the legendary American highway.

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

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

The drama of nature in full effect in this Nevada State Park.

An exotic wildlife habitat right off The Strip.

In the middle of an extremely unforgiving and desolate high desert is the most secret military facility in the world.

The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.