An unusual number plate signifies the building's saucy past.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

The remains of the medieval wall that once surrounded Paris with ties to the construction of the Louvre.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

The remaining relics of the patroness of Paris lie in a chapel under a striking double spiral staircase.

A museum dedicated to one of Paris’s most famous residents, tucked into a corner of one of the city’s most famous squares.

A museum on the history of Paris, including a set of Napoleon's toiletries, Proust's room, and relics of the Revolution.

A mechanized clock where a man fights off a dragon, crab, and rooster.

A lone cannonball remains lodged in the walls of the Hotel de Sens as a sober reminder of a revolution.

A 16th-century fountain marks the site of a lost medieval cemetery once filled with mass graves.

Notorious artist squat renovated into legal studios.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

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

A surrealist timepiece by the artist of melting clocks.

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

The narrowest street in Paris.

The “City of Stairs” sits high in the Andes, above the world’s largest underground copper mine.

The remains of this misplaced church were moved here stone by stone.

A pair of gigantic baby heads greet passengers at Atocha Station.

These ancient artifacts are a testament to the enduring significance of the bull in Spanish culture.

This enigmatic artifact is a rare depiction of an ancient Iberian noblewoman.

An iconic and controversial ancient Iberian funerary urn with a hauntingly penetrating gaze.

Paris' linguistic guide to the international language of, yes, love.

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