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

The bizarre rocks of Đavolja Varoš are the result of natural erosion.

A pair of connected skyscrapers form this symbolic gateway.

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

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

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

Structure built from the skulls of vanquished foes.

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

This exclusive resort has completely covered a tiny Balkan island in a 5-star warren of guest rooms.

A tiny church on a man-made island in the Adriatic.

A curious cave church carved into the face of a cliff.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

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.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

Rebuilt several decades ago, its striking murals prevent it from being reconsecrated as a church.

Sofia's legislative center is continuously reinventing itself.

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

A striking symbol of the Bulgarian capital.

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

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

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

Ancient serpentine sacrifice holder that has stood the test of time.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.