I remember visiting Auschwitz (1) on a beautiful summer day. It's actually quite pretty. (That's assuming you filter out the gates, the wires, the interiors.) Hell is what was done there, not a cinematic filter.

Birkenau (Auschwitz 2), on the hand, was purpose built (Auschwitz 1 was a repurposed barracks) and that really does look like Hell, even on a nice day. Every last part of it screams "this was designed for obscene purposes".