Don't think there was ever a mention that it was Auschwitz. There were numerous prison camps throughout Germany.
And why are you so certain that 8 year olds were not put to work in the camps? Though Schmol didn't seem to be doing much working anyway.
You are right, it is never mentioned in the movie. I have a habit of reading up on a flick when I'm done watching just to see what is being said about it. It's the book that mentions Auschwitz. "So, in boredom and confusion, Bruno wonders what is going on at "Out-With" (Auschwitz) and why people are always dressed in striped pyjamas there."
And to reply to the latter: "There has, however, been some discussion regarding the books' depiction of life in a Nazi concentration camp. Even the very premise of the book - that there would be a child of Shmuel's age - is, according to the critics, an unacceptable fabrication that does not reflect the reality of life in the camps. Rabbi Benjamin Blech, an outspoken critic, writes, "Note to the reader: There were no nine-year-old Jewish boys in Auschwitz -- the Nazis immediately gassed those not old enough to work."
http://en.wikipedia.org/wiki/The_Boy_in_the_Striped_Pyjamas
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I am aware that the movie intends to show a strong but albiet ultimately unfortunate ending of friendship between two children, I just dont buy into the circumstances of everything. That's all.