A 14th century bridge built as a fortress, where the devil lurks on one of its towers.

Hundreds of hidden passageways weave through the old quarters of Lyon.

A modern-day Lascaux cave underneath Paris.

A Parisian exterminator's shop whose storefront displays stuffed rats hanging from traps.

Ancient paintings known as the "Sistine Chapel of Cave Art."

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

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

One of the greatest maze designer’s greatest mazes.

A unrivaled and rather horrifying collection of wax dermatological models.

Sacked by Vikings, blessed by William the Conqueror, dealt a fatal blow during the French Revolution—these ruins have seen it all.

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.

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

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

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

This Parisian fountain is a little bit fantasy and a little bit nightclub.

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

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

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

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

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

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.

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

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