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

A pair of connected skyscrapers form this symbolic gateway.

Walk along the medieval fortifications that have been protecting Tallinn since the 14th century.

"There's nothing there," and other lies the KGB told us.

A mammoth WWII anti-air defense tower has been repurposed as a hotel with a rooftop garden.

This tunnel was an amazing feat of engineering and an economic success, but the coal mine which it served closed after only 18 years of the tunnel's use, but in WW2 the tunnel was converted to an air raid shelter

This tunnel was an amazing feat of engineering and an economic success but the coal mine which it served closed after only 18 years of the tunnel's use.

A former top secret nuclear fallout shelter now operates like a hotel stuck in the Cold War.

Near Birmingham, England three and a half miles of top-secret tunnels housed a World War II “shadow factory” and a Cold War nuclear bunker.

Along the banks of the Teltow Canal in southwestern Berlin stands one of the city’s most controversial buildings, a hulking Brutalist laboratory that looks more like a warship than a research facility.

After local authorities changed the design, the building's architect, Le Corbusier, wanted nothing to do with it.

A tree-like building perches on its trunk in the Steglitz neighborhood of Berlin.

Metro station with a claim to rock n' roll fame.

An imperial church bombed to ruins during WWII now stands as a jagged memorial.

This monumental work of art symbolizes the coming together of a previously divided city.

A historic fire call point.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

A massive relic of the communist era of Berlin.

Tiny memorials honor individual victims of the Holocaust.

One of the best-preserved pieces of DDR propaganda in Berlin.

A socialist building dedicated to teachers showcases one of the largest Soviet mosaics in the world.

A poignant memorial that traces two hundred years of German history.

A prime example of socialist modernist architecture, wrapped in a enormous fresco about the media.

Check the time in 145 countries at once with this East German relic.