In the middle of Berlin, in the old Scheunenviertel district, lies Rosa-Luxemburg-Platz - a rough place dominated by the monumental Volksbühne building. Eastern Jewish immigrants lived here before the war. It was a dreary area, but one with character. For it was here that the ideas of the 20th century were wrestled and fought over. It was about politics and world views, but also about art, cinema and theater.