A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

One of Antoni Gaudí’s earliest buildings, built between 1886 and 1890 for the industrialist Eusebi Güell.

This cemetery features modernist statues as strange as its name.

Week-long block party becomes a competition for the best decorated street.

An open-air "garden" of mural art that changes weekly.

Turntable anonymously received orphans, alms, and groceries.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

This Roman monument is surrounded by more recent construction, offering a stark contrast between ancient architecture and the modern urban landscape.

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

Berlin's old airport.

Floating swimming pool within a moored vessel.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

Berlin's natural history museum houses the world's largest mounted dinosaur and the late beloved polar bear Knut.

Berlin's beloved bear is immortalized at the Museum für Naturkunde.

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

Tiny memorials honor individual victims of the Holocaust.

This water-tower-turned-high-end-apartment building was once the site of an early Nazi concentration camp.

An old department store turned Nazi prison turned artist commune.

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

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.

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

This sculpture honors the man who was known as the "Righteous Among the Nations."

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

From cartoon characters to tiny tanks, a guerilla sculptor's little bronze statues are hidden throughout the city of Budapest.