There is an exhibition in the cellar of Eckkneipe Cafe Warschau, Sonnenallee 27: "Porträte" by K. Näslund. The owner, who works at the bar, too, hides Portraits of herself in the cellar. One for every year. Ask her for entrance.
Very interesting. I think everyone should have a cellar with Portraits of every year. In fact we have.