Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

A 400-year-old mummified arm dangles from the ceiling of St. James the Greater, serving as a warning to thieves.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

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

Macabre astrological automaton clock dating to the late 1400s.

An ornate plague column – built to celebrate life – claimed the lives of numerous artisans during its construction.

A peculiar clock commemorates a historic victory won by ringing the noonday bell an hour early.

Mummified monks and the accidentally interred, in a 17th-century crypt.

Europe's second largest ossuary wasn't discovered until 2001.

The celebrated eyesore created by starry-eyed sweethearts.

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

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

Statue of death tucked in the University of Medicine courtyard.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

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

The oldest stone house in Paris was built by its most famous alchemist.

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

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

Abandoned railway line circling the city of Paris.

A nearly 500-year-old sculpture depicts a man eating a sack of babies, and no one is sure why.

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

The former private quarters and office of Dr. Sigmund Freud now hosts a museum housing the works of the founding father of psychoanalysis.

The world's largest historic armory was established by independent citizens to defend themselves from the wars of larger forces.

The shell of a medieval fortress offers commanding views of the area it once protected.