Travel question

Image somewhat related.

So I'm going to Le Mans this year, but after the race, I've got almost two weeks to do whatever I want and go wherever I want to go. Currently, I'm thinking of doing 2 nights in Brugge, 3 or 4 nights in Amsterdam, and then I want to go to Germany. The only trouble is I have absolutely no idea where to go in Germany. I'm thinking Berlin since I'm a little bit of a WW2 buff, but I don't know if I should try to visit anywhere else in Germany while I'm there (yes, I know, the Nurburgring, but its the week before and after the 24, and the #N24 is something I'd rather get a car and go camping at).

Any tips or hints would be greatly appreciated.