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.

This Paris art space celebrates the creativity and ingenuity that springs from abject poverty, especially in Africa.

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.

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

One of the greatest maze designer’s greatest mazes.

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

A grotto-like lodge decorated with gilded mosaics, rocks and a noisy waterfall was the setting for the most sumptuous pleasure house of 1900s Europe.

Walk through spectacular aisles of hanging meat and wagon wheel–sized cheese at the world's largest wholesale food market.

Once a 19th-century brasserie, this McDonald's exterior celebrates Alsatian design and the "King of Beer."

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

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

Egyptian Revival movie palace abandoned for decades and restored in 2013.

A scandalous Art Nouveau collaboration that set Paris all atwitter at the turn of the century.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Paris' linguistic guide to the international language of, yes, love.

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.

This massive library holds what was once the largest book collection in the world.

A museum of carnival attractions where you are invited to ride the rides.

Abandoned railway line circling the city of Paris.