Auschwitz II - Birkenau, Poland.
The camp commonly known as Auschwitz. Untold people were imprisoned, and died here. For many, this track was the last journey they would ever make. Auschwitz II was created in October 1941, and liberated in January 1945 by the Russians.
Ausczhwitz (both I and II) are now museums and open to to the pubic. Words simply cannot convey the impact of visiting a place like this.
(Requires Google Earth)