Berlin's old airport.

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

Cold war icon and onetime "hole" in the iron curtain.

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

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

Copenhagen's celebrated theme park and gardens.

Swedish skyscraper with a 90° twist.

This chimerical bridge/tunnel appears to dead end right into the sea.

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

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

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

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

On Gellért Hill, this statue depicts the tragic tale of lovers divided by the Danube.

Tucked away near more famous landmarks lies a statue meant to symbolize the confluence and continuing development of human culture.

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

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

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

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

Museum dedicated to the terror regimes of Hungary.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

The last of nine massive kilns that produced many of the red bricks for buildings in Washington, D.C. and northern Virginia in the early 20th century.