Auschwitz is pretty tough but I found Dachau as bad. Maybe its because that was my first time to visit the site of a concentration camp. Auschwitz 1 was originally set up as a concentration camp but Auschwitz II or Birkenau as its also know was a death camp and nothing else. That is bleak and isolated and that got me too. The most chilling aspect of the whole experience for me was the amount of hair they still have. I think the tangiable evidence of human life really got to me there