It's hard to add anything meaningful to the other posts. This is really an incredible place, and even if you have been to other concentration camps before (like Mauthausen), Auschwitz is on a different scale. Of course you have read and seen a lot about the place, but actually seeing it is quite different. Unfortunately I had no time to go to Birkenau (there are shuttle buses, though), which I think is even more horrific. Definitely a must-visit site. By the way, I think the recent name change proposed by the Polish government to add the "German Nazi" part is a bit strange. Did anybody seriously think it was run by the Poles?