A chapel on a volcanic core, marking the end of a successful journey.

This professional clown's home is an outsider art wonderland.

This collection of French root art looks like an indoor fairy wonderland.

Beautiful carved tunnels.

One woman's decades-long obsession with the "La Fée Verte."

Massive puppet-automaton machines created by French artist collective Machines de l’Ile.

A charming flea market shop dedicated to retrofuturistic apparati.

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

The famous winding walk at Chartres is surrounded in mystery and myth.

The largest underground church in Europe.

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

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.

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

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

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

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.

Macabre astrological automaton clock dating to the late 1400s.

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

A counter-culture bookstore like no other hides in plain sight in the streets of Paris.

A haunting collection of the vanished and disappearing natural world.

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

A museum of magic with a Sadist past.