This banal Parisian entranceway is not what it seems.

This off-limits room in the National Library of France is home to a system of pneumatic tubes, once used to bring books to readers.

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

This surreal statue brings a famous French novel about a supernatural cad to arresting life.

The first green space constructed on an elevated viaduct.

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

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

The largest medical and anatomical collection in France lies hidden from the public.

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

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

Known as the "Dodo Manège," this carousel features a herd of animals that have disappeared—or may be gone soon.

Statue of death tucked in the University of Medicine courtyard.

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

Egyptian Revival movie palace abandoned for decades and restored in 2013.

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

Stroll through retro Paris while shopping for old postcards and discarded doll heads.

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

"In the Dark" Restaurant in Paris offers dinner in complete darkness.

A surrealist timepiece by the artist of melting clocks.

France's national museum of scientific and industrial instruments.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the century.

A counter-culture bookstore like no other hides in plain sight in the streets of Paris.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

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