Macabre astrological automaton clock dating to the late 1400s.

The broken skateboards that became a poignant memorial to a murdered skater.

Romania's triumphal arch looks out over Bucharest.

This ancient theater, restored in the 20th century, lives on as a venue for dramatic and musical performances.

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

A collection of art from Bulgaria's time as a communist state.

Eastern Bloc nostalgia, anybody?

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

A striking symbol of the Bulgarian capital.

Sofia's legislative center is continuously reinventing itself.

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

A Serbian church lit by chandeliers made of weapons.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

Nikola Tesla's ashes are held in a golden sphere, surrounded by his works.

Budapest's Communist-era statues, banished to the suburbs.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

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

A statue in Budapest's Liberty Square honors the former U.S. president's efforts to end the Cold War.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

A spherical "micro-nation" in the heart of Vienna.

Op-art architecture designed for happiness.