This 15th-century Serbian Orthodox monastery also contained a school for illuminating manuscripts.

A Roman monument to their own civil engineering prowess.

A well preserved medieval fortress in Vojvodina.

Religious perseverance and cultural coexistence manifest in an architectural gem that multiple wars couldn't topple.

Structure built from the skulls of vanquished foes.

This 14th century castle withstood years of battle but is now sliding off the hills into the Danube.

The most metal church of all time was built in record time because of an international, pious pissing contest.

The second-largest Jewish temple in Bulgaria was deserted after World War II, seized by the communist government and then abandoned again.

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

This massive concrete sculpture is said to be the heaviest communist monument on Earth.

This massive monument was unveiled the day Kosovo declared independence from Serbia.

A 11-foot former president stands on a Kosovo street that also bears his name.

Two distorted Romanesque columns hold aloft a mine cart in honor of laborers who died during WWII.

A futuristic, brutalist masterpiece that is also strangely prison-like.

A striking symbol of the Bulgarian capital.

This memorial to the victims of the Romanian Revolution of 1989 is often compared to a potato on a skewer.

One of the most controversial statues in Romania is an emperor with no clothes.

Romania's triumphal arch looks out over Bucharest.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

This once-derelict building is now one of the most beautiful bookstores in the world.

This solitary monastery may hold the remains of Vlad the Impaler (but probably not).

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

A misnamed well, with a deep dark past.

Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.