This 17th-century street hidden beneath Edinburgh was once a breeding ground for the black death.

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

A fortress on this island housed the mysterious prisoner known as the "Man in the Iron Mask" for more than a decade.

These unique markers designate the route American forces took during the Liberation of France.

A monument to the thousands of Canadian soldiers who died capturing the French ridge during World War I.

This symbol of the French Revolution still stands where it was first planted during the 18th-century.

A place to see how French aristocrats lived in the early 1900s.

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

This mountain trail inspired Nietzsche to complete his magnum opus.

Guests can stay at a hotel in the former French abbey where lie the tombs of King Henry II and King Richard the Lionheart.

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

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

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

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

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

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

An ancient ossuary in Rouen.

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

This medieval tower is all that remains of the castle where Joan of Arc was held before being burned at the stake.

Hundreds of secret cabinets built into the walls of legendary poisoner's private work room.

A beautiful and classically designed villa, with an hourly infestation of monsters.

The great Italian Renaissance painter was laid to rest here in the Chapel of Saint-Hubert.

This massive blockhead sculpture hides an entire library.

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.