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

The Argonaute submarine was the French navy's pride and joy in the 1950's.

This structure atop a craggy cliff in one of the most beautiful parks in Paris boasts an unbeatable view.

A French artist's vague warning hangs over Belleville.

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.

The first green space constructed on an elevated viaduct.

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

This banal Parisian entranceway is not what it seems.

France's national museum of scientific and industrial instruments.

What looks like a normal building is really a hollow facade hiding a subway vent.

A unrivaled and rather horrifying collection of wax dermatological models.

This Paris art space celebrates the creativity and ingenuity that springs from abject poverty, especially in Africa.

The spiral staircase hidden inside this giant Parisian column was likely built for Catherine de Medici's astrologer.

Notorious artist squat renovated into legal studios.

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

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

A series of abstract, silly sculptures represent the works of a great modern classical composer.

The narrowest street in Paris.

This former “ante-chamber to the guillotine” has been refurbished to illustrate the brutal history of French justice.

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.

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

This recessed garden protects thousands of mountain plants by creating its own microclimates.

Pitié-Salpêtrière was the dumping grounds for women who received the dreaded diagnosis of "hysterical."