One day my girlfriend and I went along a 'Jewish' walk along places where Jewish places to be exist in Kreuzberg. Part of the way is the path of the former Berlin wall, marked by bricks on the ground. We saw some interesting buildings along the way, and even saw some of the former death strip.
Jewish Museum, Kreuzberg
the former death strip again, not yet redeveloped, obscured by advertising
note the communist architecture, which you won't really see if you go to the touristy areas
note the communist architecture, which you won't really see if you go to the touristy areas