Roman ruins top white travertine terraces formed by ancient hot springs.

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

Largest illuminated advertisement sign in the world.

This "floating railway" is one of the world's oldest monorail systems.

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

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

This World War II bunker now survives as a documentation of the Nazi regime and war crimes.

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

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

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

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