Pitié-Salpêtrière was the dumping grounds for women who received the dreaded diagnosis of "hysterical."

A Gothic cathedral created from volcanic rocks.

At Monet's beloved home you can still see the Japanese bridge, waterlilies, and weeping willows that were the subjects of some of his most iconic paintings.

This natural French spring has been turned into a magical grotto by Roman and medieval constructions.

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

A cave dwelling that was started by the Celts, expanded by monks, and finished by knights.

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

One of the greatest maze designer’s greatest mazes.

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.

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

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

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

A museum of magic with a Sadist past.

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

A haunting collection of the vanished and disappearing natural world.

Paris' linguistic guide to the international language of, yes, love.

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

The oldest stone house in Paris was built by its most famous alchemist.

Notorious artist squat renovated into legal studios.

France's most famous cemetery, with some of its most curious tombs.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

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

HFH's slum simulation is either a noble recreation of poverty or a cringeworthy attempt at same.