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

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

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

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

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.

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

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

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

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

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

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

France's national museum of scientific and industrial instruments.

A surrealist timepiece by the artist of melting clocks.

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

Walk upon the mementos of the dead in this Parisian courtyard paved with medieval tombstones.

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

This massive library holds what was once the largest book collection in the world.

Abandoned railway line circling the city of Paris.

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

Catacombs turned marketplace.

Black cat statues guard this temple-like Egyptian revival factory.

This 1920s Dutch barge is now a floating bookstore.

This hidden green space is the city's second largest conservatory.