From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

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

This still-celebrated home was a radical architectural experiment in 3D De Stijl.

This contentious squat has stood through fire, violence, and government intervention as a hotbed of leftist protest.

Hamburg's first legal sex work is relegated to a gated street that still does not allow pedestrian women.

Hamburgers are intensely proud of their tunnel beneath the river.

This dockworkers' lunch joint has been left leaning by a century of storm floods.

Once the tallest building in the world, this abandoned church is now a monument to the destruction of WWII.

Elevated freight railway turned wildly successful urban park.

A 12th-century fortress containing some of Berlin's oldest buildings.

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.

This classic restaurant features a gorgeous mirror-clad room.

The most visited, and possibly most controversial, museum in Germany.

A beautifully eclectic mix of architectural styles.

This elaborate towering structure was once famed for its revolutionary height.

Yo, Adrian!

The world’s first penitentiary, meant to be humane, drove men insane.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A statue honors the children who fought Nazis in Poland.

Budapest's Communist-era statues, banished to the suburbs.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.