A Gothic cathedral created from volcanic rocks.

The only remaining collection of flayed figures made by French "madman" Honoré Fragonard.

Do these monsters look familiar? The gargoyles on this church are all from pop culture.

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

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

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.

An icy lake tucked among jaw-dropping alpine panoramas.

This historic island prison holds one of the dungeons from the Count of Monte Cristo even though it is a work of fiction.

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

Science fiction's grandfather has a fittingly marvelous tomb.

The curious underground history of keeping Paris clean.

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.

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

Paris' fabled purveyor of exotic taxidermy and natural history curios.

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

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

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

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.

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.

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

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