Ausschwitz, Treblinka, Majdanek, Chelmno, Belzec and Sobibor - a roll call of names which stand for the shame of the holocaust. The names of real places, where the Nazis murdered millions of Jews and other people they considered undesirable. In many cases, such as at Sobibor, the Nazis later tried to cover up all traces of the atrocities that had occured. But the victims have not been forgotten.