This otherworldly French waterfall looks like its waters have turned to stone.

Miles of man-made caves and tunnels are currently used for cultivating mushrooms.

Perfume museum and library.

Despite centuries of architectural innovation, this French castle is being built like it's the 13th century.

The sunken structure looks like the victim of a catastrophic flood.

A French library that makes sure its love of books is writ large... giant in fact.

A centuries-old complex of hand-dug stone chambers has sheltered locals in times of trouble.

Former hunting lodge of a duke who was an avid collector of impressionist works.

This crumbling, graffiti-covered mansion sits tantalizingly within reach of the proletariat who frequent a public park.

One of the world's most complex timepieces.

A swath of France so devastated by war it is still forbidden to go there.

The Church of the Annunciation was carved into the face of a cliff, just like the rest of the town of Haute-Isle.

A French valley with forests so lush it was nicknamed "the Small Amazonia of the Pyrenees."

The 16th-century church was kept in its ruined state as a reminder of the casualties of World War I.

A medieval church with largest and oldest collection of Renaissance frescoes in France.

An odd museum dedicated to French fakes.

The post-apocalyptic remnants of a bucolic town ruined by a plane crash.

Hundreds of dwarf beeches create an unusual, haunting forest in the north of France.

An abandoned beach resort in Normandy reclaimed by artists.

The personal library of the founder of modern neurology is open to visitors.

Since ancient times these picturesque springs have been providing bathers with healing waters.

The remains of 40,000 humans, meticulously stacked in a tiny churchyard shed.

The oldest and smallest cemetery in Paris is only open to the public twice a year.

The encased skull that is widely believed to belong to St. John the Baptist.