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

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

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

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

Yo, Adrian!

The yawning maw of this pagan visage is said to bite off the hands of liars.

2300-year-old Roman road connecting the empire.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

Baroque celebration of the end of the Great Plague of Vienna.

An elaborate gift from Claus Spreckels is now a piece of San Francisco history.

Art in the form of a winding, man made crack in stone.

Gold Rush ship-turned-hotel buried underneath San Francisco's financial district.

A mysterious painting of the self-declared Emperor of the United States watches over a local hof-brau.

A Barbary Coast watering hole built into a Gold Rush shipwreck.

The restored and active Victorian-era final resting place of San Francisco.

A 140-year-old castle with underground caves hidden in San Francisco.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

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

Go inside to really appreciate this 500-year-old technological masterpiece.

The most famous location in China was home to whole dynasties worth of imperial rulers.

Storyville was New Orleans' historic red light district and hotbed of jazz music, sometimes referred to simply as "The District."

New Orleans' famous cemetery, located on the site of a former race track.

Famously misunderstood wonder of the ancient world