According to a book about the numbers of people died at Auschwitz, atleast 4.25 Million people died in Auschwitz II (Birkenau).
Auschwitz I is located in Poland, and was originally used as a prison for the "outcasts of life" such as people with disabilities, deformities, gypsies, homosexuals and Jews (unfortunately, of course). Auschwitz II - Birkenau was started in 1941 and was larger and more "deadly and famous" than Auschwitz I. Auschwitz II is what most people referr to when they say "Auschwitz". Auschqitz III - Monowitz was a chemical plant where most of the workers were slave labourers. It is in use as a chemicals factory. Tours for the public are held at the remains of Auschwitz I and II. http://en.wikipedia.org/wiki/Auschwitz
Auschwitz I Stammlager, Auschwitz II Birkenau and Auschwitz III Monowitz
Large sections of Auschwitz I and II have been preserved as a museum. -------------- It is at the end of the railway line at Auschwitz II (Birkenau) between where Krematoria II and Krematoria III stood.
# Auschwitz II, where he and his father were selected for work at Auschwitz III (Monowitz, sometimes also called Buna). # Buchenwald, where his father died.
Birkenau
Auschwitz II (also known as Birkenau) was on the main site, about 1.5 miles from Auschwitz I. Please see the related question.
Parts of Auschwitz I and II have been turned into a museum.
It was at Auschwitz, about four miles from Auschwitz II.
Auschwitz II, Buna (=Auschwitz III), Gleiwitz, Buchenwald. He only passed briefly through Auschwitz II and Gleiwitz.
Auschwitz was around during World War II.
It had 3 sections. Auschwitz-I, which served as a working camp. Auschwitz II-Birkenau, the death camp. Auschwitz-III, it was used to provide slave labor to the nearby industry.
From early 1942 onwards, there were three camps on the main site at Auschwitz and the number of sub-camps (off the main site) grew to 45. The main site included the extermination camp at Birkenau (Auschwitz II).