Tierpark Friedrichsfelde in the former East Berlin is Europe’s largest landscape zoo: http://www.tierpark-berlin.de/tierpark.html. It is not quite as centrally located as the zoo near Kurfürstendamm, but easily reached by public transport. A lot of walking is involved in a visit, sometimes in forest-like terrain, so comfortable shoes are advised. Here are some photos from my visit there in July 2012:
