Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

This cathedral hides a sculpted dog that determines your fate and an unexploded shell from World War II.

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.

Tiny memorials honor individual victims of the Holocaust.

These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.

The celebrated eyesore created by starry-eyed sweethearts.

This easily overlooked memorial immortalizes the scars from the 1956 Hungarian Revolution.

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

Berlin's old airport.

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

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

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.

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.

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

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

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

Buried five stories underground, this Soviet bunker is packed with gas masks and Cold War paraphernalia.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”