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

Rainbow arches made of shipping containers grace the entrance to one of France's largest seaports.

A quaint medieval millhouse hovers surprisingly above the waters of the Seine.

At Monet's beloved home you can still see the Japanese bridge, waterlilies, and weeping willows that were the subjects of some of his most iconic paintings.

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

A small house sits between two huge rocks, with its back to the sea.

This enormous "cloth of the conquest" depicts the Norman invasion of England in mind-blowing detail.

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

This 1,400-year-old abbey was once a powerhouse for music and intellectualism known across Normandy.

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

A mosaic-tiled house built by graveyard sweeper Raymond Isidore.

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

An ancient ossuary in Rouen.

This 18th-century pirates lair has been transformed into a museum and luxury event space.

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

An effigy of a trapped paratrooper dangles from a Normandy church to commemorate one remarkable D-Day event.

Bloodstains can still be seen in this medieval church where two medics saved lives on D-Day.

The Lone Star plaque hangs in a bombed-out bunker in Normandy to honor a Texan colonel's heroic actions on D-Day.

This place bears witness to the loss of many lives during WWII, and stands in stark contrast to the American Cemetery.

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

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

An art-filled botanical garden and former dyeworks hiding in plain sight.

This mountaintop mariner’s church is packed with model ships and nautical art while hosting an annual maritime festivity for the townsfolk below.

One of the oldest and largest wooden churches in France was very evidently constructed by shipbuilders.