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

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

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

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

France's national museum of scientific and industrial instruments.

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

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

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

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

A haunting collection of the vanished and disappearing natural world.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

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

This massive library holds what was once the largest book collection in the world.

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

Abandoned railway line circling the city of Paris.

Notorious artist squat renovated into legal studios.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

This stunning natural double arch, the largest in the Alps, went undiscovered until 2005.

The shape of this old salt factory complex was inspired by the course of the Sun.

One of the world's most complex timepieces.

The somewhat misnamed 'Garden of Shells' lovingly built from found objects.

The castle was reconstructed to fit Kaiser Wilhelm II's romanticized vision of the Middle Ages.

There has been an astronomical clock on this spot since the 14th century.

This "social palace" housing complex created a relatively stable and self-contained worker's society... for a time.