On the recent trip to Poland and Israel we got to spend an afternoon visiting the museum and site at Auschwitz.  Needless to say I wasn't prepared for the weight of the site and despite full photo gear in tow I managed to mostly refrain from taking too many pictures.  I think this will probably the only one I post...It's truly an important site to visit and the memorial at Birkenau states the following in about a dozen languages which really sums up the importance of the site today:

For ever let this place be a cry of despair and a warning to humanity, where the Nazis murdered about one and a half million men, women, and children, mainly Jews from various countries of Europe.

Auschwitz-Birkenau 1940 - 1945

You can see from this vantage point the SS Guard stand in the distance where the Rail cars entered the site and dropped people off.  This Rail Car is sitting on one of the tracks still standing today and the gravel area to the right would be where people exited the cars and were then processed into the camp.