Avant garde house of Pierre Cardin on the Cote d’Azur.

This massive blockhead sculpture hides an entire library.

Historic medieval fortified city in southwest France.

This recessed garden protects thousands of mountain plants by creating its own microclimates.

Lyon, France is home to two remarkably preserved Roman theaters, one dating back to 15 BCE.

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.

Despite being considered a thoroughly American sport, basketball's oldest surviving playing field is found in the basement of a Paris YMCA.

This Parisian gem is one of the most incredible ethnographic museums in the world.

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

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

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

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.

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

An icy lake tucked among jaw-dropping alpine panoramas.

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

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

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 series of abstract, silly sculptures represent the works of a great modern classical composer.

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

Sacked by Vikings, blessed by William the Conqueror, dealt a fatal blow during the French Revolution—these ruins have seen it all.

A modern-day Lascaux cave underneath Paris.

The curious underground history of keeping Paris clean.

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