A plaque marks the spot where the saint was shoved off the Charles Bridge and into the river.

Hundreds of thousands of concrete bunkers crowd Albania long after the fall of Communism.

Stockholm's deepest subway station is also a stunning ecological wonder.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

It houses the remains of a 17th-century version of the Titanic.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

A former fortified tower now houses a collection of classic communications equipment.

Experience what life was like in Ireland during the Viking and medieval ages.

Dublin's most modern, visually spectacular bridge is modeled after Ireland's national emblem.

An ancient knight and a symbol of the city's freedom.

A ruined castle stands atop a hill surrounded by dragon lore.

Sofia's legislative center is continuously reinventing itself.

A vast Communist-era exhibition space in the Bulgarian capital.

"Holy Wisdom" overlooks the city that became its namesake.

"Unity, Creativity, Beauty."

A striking symbol of the Bulgarian capital.

A Bulgarian monument to Russia's role in World War II is constantly being painted in pop culture protest.

Enormous sandstone towers loom within a Czech forest.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

The partially submerged ruins of a white marble quarry used in ancient Greece for over 1,200 years.

One of the largest single-span stone-arch bridges in the Balkans looks like something straight out of a fairytale.

Ancient Greek oracle of the dead.

A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.