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

A 14th-century Serbian Orthodox church that was once converted into a mosque under the much-disfavored Ottoman Empire.

An unfinished Serbian Orthodox church with 1,389 golden crosses planned to represent the Battle of Kosovo.

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.

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

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

This memorial to a murdered empress took 20 years to design, then spent 30 years hidden away in storage.

Hungarian Jews were ghettoized during the Second World War, but little remains of the original wall that closed the Jewish people off from the rest of the city.

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

The geographical center of Budapest is marked with a 10-foot-tall stylized zero.

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

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

A random tree outside a Budapest hotel has become a DIY shrine to the late singer.

This off-beat, quirky communism-themed bar isn't afraid to poke fun at its history.

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

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

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

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

Towering metal swords commemorate a 12th-century victory.

Abandoned museum from the last days of Soviet domination, with a unique Brutalist design.

Despite being tiny and rural this Georgian airport looks like a sci-fi boondoggle.

With over 10,000 lights, this engineering marvel lights up the city after dark.

At this rare mosque in Tbilisi, Sunni and Shia Muslims pray side by side.