This modern French ossuary contains the jumbled bones of 130,000 WWI soldiers.

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

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

For hundreds of years, automatons moving to metallic music have been marking the passage of time.

This museum in a Paris apartment gives a unique look at the iconic French singer's life.

This banal Parisian entranceway is not what it seems.

This off-limits room in the National Library of France is home to a system of pneumatic tubes, once used to bring books to readers.

A Gothic cathedral created from volcanic rocks.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

Do these monsters look familiar? The gargoyles on this church are all from pop culture.

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

The former home of France's controversial pop maestro is almost completely covered in ever-changing tributes and graffiti.

This salt marsh in Southern France is as pink as the flamingos that inhabit it.

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

Two awe-inspiring globes from the reign of the Sun King hang from the ceiling of France's national library.

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.

This historic island prison holds one of the dungeons from the Count of Monte Cristo even though it is a work of fiction.

An icy lake tucked among jaw-dropping alpine panoramas.

Pitié-Salpêtrière was the dumping grounds for women who received the dreaded diagnosis of "hysterical."

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

A modern-day Lascaux cave underneath Paris.

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

One of the last umbrella repair shops in Paris upholds the nostalgic art of umbrella making.

Ancient paintings known as the "Sistine Chapel of Cave Art."