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

The largest crypt ever constructed in France was built in the 11th century on an ancient Druid sacred site.

From carts to cars, this leftover Roman bridge in France has managed to survive for centuries.

An underground city of ancient quarry tunnels hid thousands of Allied soldiers in WWI.

Natural mummies hidden in the crypt of a medieval French church.

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

There is a strange little carving of a person seemingly crushed by a pillar behind the remains of St. Thomas Aquinas.

His "Lionheart" is entombed separately from the rest of his body.

Tens of thousands of ancient rock carvings hidden in the heart of a French national park.

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

A memorial to the nearly 10,000 American soldiers laid to rest on the beaches of Normandy during WWII.

This modern museum of Mediterranean culture is surrounded by a surreal concrete honeycomb.

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

The opulent home that inspired Tintin's Marlinspike Hall and the adventures within.

Green labyrinth formed by a karstic maze hidden in a preserved oak forest.

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

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

Underneath a chalk hill in France lies what Hitler hoped would be the underground launching base for a devastating new weapon.

The construction of a tram line unveiled hidden remnants of the old medieval city.

One of the world's most complex timepieces.

Trek into the depths of the cave where 17,000-year-old paintings exist alongside 400-year-old graffiti.

Nicknamed the "Museum of Horrors," this French anatomical collection has been fascinating visitors for over a century.

A unique underground structure dating back to the 1st century BC.

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