http://culture.pl/pl/artykul/co-pamieta-warszawa
This is the ghetto area.
And these are before/after photos, all taken in the center of Warsaw: http://wczorajidzis.blogspot.com/2010/06/3-w-1-1945-1971-201...
I've always been hoping that we can learn from past mistakes, but recent inaction of western europe towards Putin's war with Ukraine has me deeply worried.