Back in the 60's I was talking to a guy who helped liberate some of these camps. Then he got involved in administration of the displaced persons after the war.

He was telling me about this camp and that camp and I asked him just how many there were. I don't remember the number he told me, but he ended his statement with, "That we know about."

He figured the real number would never be known since so many of the sites were 'behind the wall' as Eastern Europe was referred to at the time, but he had no doubt that there had been many more Camps in use than anyone had found up to that date.