This submersible road connecting a French island to the mainland is lined with safety towers for when the tide strands travelers.

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

A bike train runs along a disused railway line through the tranquil French countryside.

These crumbling Nazi artillery bunkers are now fair game for massive graffiti projects.

One of the largest ochre quarries in the world, hidden in a limestone landscape.

An ancient monastery, a locked room, and a mysterious book heist.

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

A tiled, multi-level garden of survival in Lyon.

What looks like a normal building is really a hollow facade hiding a subway vent.

Ivy-covered Medieval tunnels cut through this charming town in France's Loire Valley.

A medieval military street hidden beneath a charming French fishing village.

A well-preserved medieval village nested on a rocky outcrop and surrounded by a network of cliffs, natural bridges and canyons.

An aluminum skeleton brings Chinese mythology to the French shore.

A natural arch carved by a river gave its name to the so-called "Cave of Forgotten Dreams."

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

The mental institution where Van Gogh created some of his most famous work now allows guests to walk in the artist's footsteps.

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

This structure atop a craggy cliff in one of the most beautiful parks in Paris boasts an unbeatable view.

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.

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

An icy lake tucked among jaw-dropping alpine panoramas.

This banal Parisian entranceway is not what it seems.

One of the greatest maze designer’s greatest mazes.

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