The site of a concentration camp where inmates were made to take part in one of the largest counterfeiting operations in history is now hauntingly empty.

Germany's Glienicke Bridge has a shady history of clandestine meetings, espionage, and spycraft.

The "Prussian Versailles" that is as glorious today as when it was built.

If you visit the burial place of King Frederick the Great, you'll likely find a couple of potatoes sitting on his tombstone.

Cold war icon and onetime "hole" in the iron curtain.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

A memorial in the Tiergarten is a reminder of the suffering inflicted on homosexuals by the Nazi regime.

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

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

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.

After a nearly successful attempt on Hitler's life, the conspirators met their fate in the courtyard of this Berlin building.

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

This historic black and white monastery is one of Bulgaria's architectural jewels.

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

Sofia's legislative center is continuously reinventing itself.

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.

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

On the wall of this medieval walkway, a symbol of the Spanish Inquisition.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

This cemetery features modernist statues as strange as its name.

Holy Grotto of Montserrat Monastery holds one of Europe's mysterious black Madonnas.

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

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