Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

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

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Millions of years of oxidation make a drive down this winding Death Valley road surprisingly colorful.

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

A church of bones, decorated with 40,000 human skeletons.

Macabre astrological automaton clock dating to the late 1400s.

Old-fashioned knowledge and modern engineering create the world's only rotating boatlift.

Ancient cliffs resembling a kilt on Scotland's second largest island emit an entrancing sound.

An ancient Scottish rock formation said to be the gravesite of a giant remains ensconced in legend and intrigue.

France's most famous cemetery, with some of its most curious tombs.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The farthest northwesterly point of the British mainland is one of the most remote places in the Scottish Highlands.

These fantastically named natural pools look like something out of a Scottish myth.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

A seven-century-old jail tells a not-so-pleasant history of crime and punishment.

Now a museum, this building was once a 14th-century monastery and the place where the founder of the Dutch nation lived and was assassinated.