Auschwitz has strange smell?

I was just there a few days ago, and when I entered the camp, I noticed right away that there was a strange odor. It kind of smelled like burning, a little sweet, and the rest was indescribable. I know I wasn't imagining it because another person commented on the same thing. I know the burning of the Jews was ages ago, but I wonder.....maybe it is reminence of that? I doubt it but can anyone explain this? Thank you!!!