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

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

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

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

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.

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

Noirish green neon marks the location of one of the oldest private detective agencies in France.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

Natural history museum celebrating biodiversity with a parade of taxidermy animals.

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

The subterranean "lake" below the Paris opera house inspired the Phantom of the Opera's lair.

A mechanized clock where a man fights off a dragon, crab, and rooster.

Down a cobblestone alleyway is a museum dedicated to Romanticism, with a secret garden.

Behind the pink curtain, Au Bonheur du Jour, an art gallery of erotic archives.

Walk upon the mementos of the dead in this Parisian courtyard paved with medieval tombstones.

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

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

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

This frog-themed restaurant was frequented by Picasso, Saint-Exupéry, and more.

Danish whalers once brought back whale bones to use as building materials in places where wood was scarce.

A Danish fisherman spent 25 years covering nearly every inch of his home with tens of thousands of shells as a gift to his wife.

Faith and landscaping come together in a small Danish haven dubbed the "Bible Garden."

This contemplative sculpture made out of old machine parts is meant to be the first in a series of sculptures around the world.