A unique seaside cave where Aleister Crowley faked his own death.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

These enduring murals depicting a distinctly Marxist tribute to capitalism could not even be defeated by McCarthyism.

Controversial tribute to the heavyweight champion boxer who grew up in Detroit.

An obelisk marks the exact center of the continent, as per the calculations of the legendary Brazilian explorer Cândido Rondon.

A kaleidoscopic warehouse-maze of handmade neon signs.

A beautiful young girl said to have been buried alive in her coffin…

This bar named after the world's first mixed cocktail was home to one of New Orleans' most notorious politicians.

Every equinox this Maya pyramid puts on a spooky ancient light show.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

The prototype for all Nazi concentration camps.

The footprint of a frustrated devil in Munich's Cathedral.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

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

Two stunning 17th-century libraries and a cabinet of curiosities.

Increasingly decayed figures stand as a powerful reminder of the human costs of Czech Communism.

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

A turn of the century building boasting some of the most beautiful art nouveau architecture in Prague.

This Prague museum collects brutalist relics and memories from the country's former Soviet rule.

A mocking tribute to the past and modern leadership of Prague.

Monument to a suicide protesting the Soviet invasion.

The final resting place of the great navigator, or maybe his brother.