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

A Serbian church lit by chandeliers made of weapons.

The metal leaves on this tree are engraved with the names of Holocaust victims.

A plaque bearing the names of those who dedicated themselves to protecting Budapest's Jewish population during World War II.

A triumphant marble and bronze fountain depicting a 15th-century Hungarian king and his hunting party.

The holes in this wall provide a glimpse into Jewish life in Budapest, both past and present.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

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.

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

An homage to the medieval rulers of Bulgaria.

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

Sofia's legislative center is continuously reinventing itself.

Underneath this Byzantinian church lies a necropolis filled with ancient tombs and the ruins of previous churches.

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.

No one is sure if the world's fourth-largest diamond had been found in a rubbish heap or was pawned by Napoleon's mom.

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

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

This daunting 1st century fortress was purportedly the site of one of the most dramatic revolts of the Jewish-Roman wars.

The tallest waterfall in the Judean Desert is named for its connection to a biblical figure.

Roman ruins top white travertine terraces formed by ancient hot springs.

This arch granting triumphal entrance into Antalya was designed to honor the emperor's visit.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.