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

The first green space constructed on an elevated viaduct.

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.

Statue of death tucked in the University of Medicine courtyard.

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

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

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

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

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

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

A surrealist timepiece by the artist of melting clocks.

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

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

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

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

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

France's national museum of scientific and industrial instruments.

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