I'll, foolishly perhaps, assume you are naive and not stupid or shilling. There are mass graves at Belsen, Buchenwald, Dachau and perhaps other camps, these graves were for the large numbers of prisoners that died at the end of the war due to disease, 35,000 at Belsen alone (ref. -
http://www.usatoday.com/news/world/2006-11-19-holocaust-papers_x.htm) You can read the history of Belsen on wiki, it was not a hoax death camp, no Jews were killed at Belsen as part of an attempt to exterminate Jews, they died at the end of the war as a result of disease. If you don't understand the difference, then you are stupid or a shill. So, these graves are not evidence for the holohoax.