This building’s ghostly exterior reflects its former lives as a prison, school, and funeral home.

This tiny hotel perched atop a 50-foot tower really puts things into perspective.

Remains of the artificial harbours invented for the Allied invasion of Normandy can still be seen at sea.

Resting on a hill overlooking the coast, these medieval ruins look completely deserted save for their restored chapel.

The castle was reconstructed to fit Kaiser Wilhelm II's romanticized vision of the Middle Ages.

A daring D-Day assault by U.S. Army Rangers is commemorated atop the high cliffs of this strategic point.

These medieval ruins have survived since the 12th century, even providing shelter from the Nazis.

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

The birthplace of the ferocious William the Conqueror, this castle is awash in medieval history.

This narrow path was cut right into a French mountainside to feed the country's early naval expansion.

Miles of man-made caves and tunnels are currently used for cultivating mushrooms.

Bits of architecture from a town destroyed in World War I now decorate this hotel garden.

A French library that makes sure its love of books is writ large... giant in fact.

These crumbling Nazi artillery bunkers are now fair game for massive graffiti projects.

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

The Church of the Annunciation was carved into the face of a cliff, just like the rest of the town of Haute-Isle.

This futuristic observatory at the top of the Pyrénées offers unrivaled views.

A tiled, multi-level garden of survival in Lyon.

The sunken structure looks like the victim of a catastrophic flood.

Hundreds of prehistoric stones, arranged in perfect lines in a French field.

An enchanting work of outsider art, full of whimsical sculptures and carvings.

The post-apocalyptic remnants of a bucolic town ruined by a plane crash.

Since ancient times these picturesque springs have been providing bathers with healing waters.

This French castle is said to have once held the Holy Grail but is now a gorgeous mountaintop ruin.