America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

A daily replay of the experiment that proved the rotation of the Earth.

Yo, Adrian!

World's first "penitentiary," meant to be humane, drove men insane.

The only remaining collection of flayed figures made by French "madman" Honoré Fragonard.

In this Parisian garden's grotesque former life as a zoo it fed exotic animals to the bourgeois and put humans on exhibit.

A modern-day Lascaux cave underneath Paris.

This Parisian gem is one of the most incredible ethnographic museums in the world.

The curious underground history of keeping Paris clean.

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

This bridge was constructed from the rubble of the infamous Bastille.

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

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

The celebrated eyesore created by starry-eyed sweethearts.

A favorite Paris bar for U.S. expats, including Gershwin, Hemingway, and James Bond.

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

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

If you look closely at the oldest bridge in Paris, you might notice hundreds of ugly faces leering from its sides.

Original cabaret handbills, posters, and feline artwork are a purrfect highlight of the Museum of Montmartre.

A museum of magic with a Sadist past.

A magical, macabre wax museum, beloved by locals, uses real artifacts to depict an assassination from the French Revolution.

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

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

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