Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

Breathtaking and huge 430 year old maps of Italy.

France's most famous cemetery, with some of its most curious tombs.

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

A tunnel that brings more than a century of history to life from the deepest parts of the Niagara Gorge.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

This former guildhall with a bacon-like exterior is now home to a museum covering 600 years of Antwerp's musical history.

This magnificent market stands as a poignant symbol of the suffering caused by the Spanish Civil War.

This cemetery features modernist statues as strange as its name.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

This large copper bolt represents the benchmark for measuring sea levels in most of Europe.

It appears as if a man is standing behind this giant airport clock, painting the hands in real time.

This gorgeous reading room houses the oldest and largest art history library in the Netherlands.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

A historic fire call point.

For patriotic Russians, this memorial honoring the Soviet soldiers who died liberating Berlin in 1945 is the most sacred location outside of Russia.

Reminders of the Battle of Berlin still scar the railway.

Metro station with a claim to rock n' roll fame.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

Berlin's old airport.

The walls of Germany's Parliament still show the scars of the Red Army takeover in World War II.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

An astonishingly accurate water clock that doubles as an hourly spectacle in this Berlin shopping area.

The site where a plot to assassinate Hitler was planned—and its conspirators were executed—is now a powerful memorial to the German resistance during World War II.