A French artist's vague warning hangs over Belleville.

The abandoned remains of this Victorian brewery hide crumbling bowling alleys and rusting industrial gear.

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

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

France's national museum of scientific and industrial instruments.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

The last remnants of a massive medieval wall that once encompassed the city of Berlin.

The skeletal frame of a decommissioned gas-pumping station offers breathtaking views of greater Berlin.

The walls of Germany's Parliament still show the scars of the Red Army takeover in World War II.

Berlin's old airport.

Floating swimming pool within a moored vessel.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

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

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

A fascinating insight into daily life in the Eastern Bloc.

Where once there was a train station bathroom, there is now this German burger joint.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

Art and a pun, all in one.

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

This Dresden church was purposely rebuilt Protestant after being demolished in World War II.

An eerie, derelict amusement park in Berlin.

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

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