If anyone has ever had the chance to visit the Monument to the Murdered Jews of Europe in Berlin, it's a powerful reminder. A whole block of downtown Berlin, right next to the Brandenburg gate, probably the most expensive land in Germany, is filled with varying heights of concrete "pillars" for lack of a better term. It's like a field of the things, and as you walk into them, they get higher and higher, covering your head and closing in from all sides, supposed to mimic the feeling of entrapment and impending doom that the Jews would have felt under the Hitler regime. Very powerful, and very cool.
I've got a couple of photos of it up:
here and
here.