When I was about 12-13 my Dad took us on a tour of Europe (He was Army & stationed at Baumholder). The tour included Dachau - a very sobering experience, even for a young man.
My grandfather was in the Army and among the early wave of American troops to enter the camps. He spoke only a few times to me about the horror he saw over there. I know he’d find the idea of a wall decoration of a concentration camp to be the worst idea. Someone thought it was, though.
And we wonder how things happen again.