The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

A slice of central Asia in the middle of Berlin.

This incredible stone temple is a monument to death, victory, and fantasy architecture.

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.

Uh, pardon me, ma'am, but I couldn't help noticing that there's a Columbo statue in the middle of Budapest.

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

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

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

Hundreds of stone stairs and a winding medieval bridge connect this haunting Spanish island to the mainland.

Two towns are linked by an engineering marvel masquerading as a boring suspension bridge.

Giant topiary dog once played a role in a terrorist bomb plot.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

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

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Now an entertainment complex, the Lingotto building was once an avant-garde auto factory with a test track on the roof.

A fake medieval village in the middle of Turin.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

Berlin's old airport.

A monument to the man who almost killed Hitler.

Tiny memorials honor individual victims of the Holocaust.

The former home of a mad diplomat is said to still be marked in bloody, arcane scrawls.