The former home of France's controversial pop maestro is almost completely covered in ever-changing tributes and graffiti.

Noirish green neon marks the location of one of the oldest private detective agencies in France.

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

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

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

The subterranean "lake" below the Paris opera house inspired the Phantom of the Opera's lair.

An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

In the best of all possible worlds, everyone will get a chance to see this statue in which Voltaire's heart is interred.

A grotto-like lodge decorated with gilded mosaics, rocks and a noisy waterfall was the setting for the most sumptuous pleasure house of 1900s Europe.

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

This Parisian fountain is a little bit fantasy and a little bit nightclub.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

A majestic lion statue guards this Parisian botanical garden, and feeds on an unsettling item.

The history of radiation is on safe display at the foot of a radiation science laboratory.

A subterranean shelter remains intact under a busy Paris railway station.

Statue of death tucked in the University of Medicine courtyard.

Down a cobblestone alleyway is a museum dedicated to Romanticism, with a secret garden.

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

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

Indents in the pavement are all that remain from a grisly death machine in Paris.

Behind the pink curtain, Au Bonheur du Jour, an art gallery of erotic archives.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

19th century pendulum and a clock restored by a rogue group of guerilla artists.

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