The curious underground history of keeping Paris clean.

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

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

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

A unrivaled and rather horrifying collection of wax dermatological models.

The first green space constructed on an elevated viaduct.

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

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

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

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.

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

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

This Parisian café sticks almost exclusively to an ethos of reuse.

Paris' fabled purveyor of exotic taxidermy and natural history curios.

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.

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

This museum houses an imposing skeleton army comprised of creatures great and small.

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

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

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

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.