These red marks, seemingly placed at random, are in fact not.

The ruins of a medieval castle linked to the murderous French lord that inspired the famous legend of Bluebeard.

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

This imposing castle has stood for nearly a thousand years.

The ruins of an abandoned cemetery are among the last remnants of the old village of La Boulaye before a wealthy landowner had it relocated.

These ramparts, once lined with towers, were constructed in defense of Beaune.

The shape of this old salt factory complex was inspired by the course of the Sun.

Over 3km of caverns and caves at the Switzerland-France border contain the largest underground river in Central Europe.

A suspended footbridge allows for traversing this gorge carved through the French Alps.

A fortified palace in the shape of a ship on the Thiou river.

Trek up this glacier before it disappears.

An icy lake tucked among jaw-dropping alpine panoramas.

A gothic church dedicated to the love of wine.

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

For those late-night mollusk cravings.

A massive, secret marina for the Nazis' most formidable weapon in the Atlantic.

Fighting the British and making game shows for over 150 years.

A castle-like sea fort from the 17th century is now a museum to oyster farming.

A quarry cum sculpture park where the works of art are chiseled into the very walls.

This 5,000-year-old tomb once had its own hinged door.

A tiny, forgotten park of surrealist sculptures in Angouleme.

The vibrant buildings in the “capital of the comic strip” celebrate the art form that made it famous.

A Gothic cathedral created from volcanic rocks.

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