In the shadow of a former battleground, the resting place for nearly 2,000 soldiers who died in World War I.

This memorial museum chronicles the apocalyptic destruction of the First World War.

A moving memorial to the fallen and missing from WWI trenches.

The site where one of the most famous poems of World War I was composed is preserved to honor the legacy of the work.

A rare example of World War I trenches from the British front.

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

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.

The mummified heart of Louis XVII, the lost dauphin of the French Revolution.

The video game-themed street art first popped up in the French city.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

The narrowest street in Paris.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

This stack of stones honors a murdered 18th-century woman.

The most loyal of little dogs, or a Victorian era publicity stunt?

This obscure walkway links Edinburgh’s Old Town with one of the city's prime vantage points.

A labyrinthine network of chambers with a storied past hides below Edinburgh's South Bridge.

Protecting the dead from opportunistic body snatchers.

The final resting place of soldiers' loyal canine companions.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

The castle still holds traces of the abandoned Roman fort it was built atop.