Miniatur Wunderland!

The main attraction in Hamburg for me was the Miniatur Wunderland, the world's most extensive model railway. There are three floors and 7 different themed worlds, including Switzerland, Hamburg itself, and America. But with the addition of a working model airport, hundreds of little computer controlled cars and trucks with working lights, a cruise ship, and even a space shuttle, it has grown into something beyond just trains. And they're planning on adding Italy and Africa in the coming years!
I loved it! To say "great attention to detail" seems an understatement. Attention to their attention to detail is the whole attraction. The best part was the little tableaux you would happen upon if you looked close enough and cared to piece the story together. So much fun.