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.

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

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.

Statue of death tucked in the University of Medicine courtyard.

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.

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

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.

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

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

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

A surrealist timepiece by the artist of melting clocks.

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

A museum of magic with a Sadist past.

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

A mechanized clock where a man fights off a dragon, crab, and rooster.

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

One of the oldest medical collections in Europe focusing on rare surgical instruments.

A museum of carnival attractions where you are invited to ride the rides.

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

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