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

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

The video game-themed street art first popped up in the French city.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

A copy of the famous statue can be found in this Florence piazza, along with one of the most breathtaking views of the city below.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

Renaissance hospital featuring a rotating door into which unwanted babies were dropped.

A slightly creepy gallery of plaster cast models in the same museum as Michelangelo's David.

Two stone columns flank the grand Venice square, but there were supposed to be three.

One of the world's oldest working clocks is curiously missing the Zodiac sign of Libra.

This massive subterranean fissure is known as the "underground Grand Canyon."

A whimsical bridge adorned with decorative dragons.

Local legend says Isaac Newton built this footbridge without any screws, bolts, or nails.

Stalinist skyscraper built with help of cryotechnology.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

Eighty million natural history specimens call this gargantuan museum home.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

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

This easily overlooked memorial immortalizes the scars from the 1956 Hungarian Revolution.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

A 19th-century artistocrat's mansion, turned into a library, hidden in a modern library.

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