A charming flea market shop dedicated to retrofuturistic apparati.

A modern-day Lascaux cave underneath Paris.

Artist and musician Will Menter creates musical sculptures.

This French "sea of rocks" is packed with stunning rock formations and its own medieval castle.

A massive, secret marina for the Nazis' most formidable weapon in the Atlantic.

Beneath the city of Lourdes, France is a massive, concrete church.

A daring D-Day assault by U.S. Army Rangers is commemorated atop the high cliffs of this strategic point.

Bordered by forest on three sides and the ocean on the other, the Great Dune of Pilat is the highest sand dune in Europe.

A remote hilltop covered in giant monoliths haunts the Brittany countryside.

Remains of the artificial harbours invented for the Allied invasion of Normandy can still be seen at sea.

This former limestone quarry is now a subterranean wonderland of grand stonework.

Abandoned blockhouses from Nazi Germany's Atlantic Wall erode into the sea on a French beach.

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

An antique curios dealer and hybrid taxidermist.

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

A beautiful and classically designed villa, with an hourly infestation of monsters.

This massive blockhead sculpture hides an entire library.

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

A neighborhood church's unusual abstract stained glass was the final project of avant-garde artist Jean Cocteau.

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

The world's largest boar is a huge steel titan found at a French rest stop.

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

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

A garden of massive sculptures sits in Jean Lindard's backyard.