What should I do in Germany?

[Thythe]

I know nothing about what to do in Germany and am going there in early December. I'll only be there for a week and will probably spend a day or two in Amsterdam. Besides for that, what should I do? I'll have a train pass for access to the whole country but don't want to waste time on boring attractions. I'm in to historical type stuff (Berlin Wall, etc) and outdoors kind of stuff. Shopping, art, opera type stuff is definitely not what I want. Thanks for the help!