in world war 2 one of the most known concentration camps was Auschwitz  there Dr Mendele worked he was very interested in doing experiments on people mostly on Jews and Pols. Sometimes they said that the prisoners are going to get a shower but actually the got locked in a room where the german soldiers put in a gas and the prisoners would choke to death.

He also did experiments on twins and he stabbed needles in there eyeballs to make there eye colour change and he sew 2 twins together one experiment was also the sleeping experiment this is where Auschwits is in Kraków a couple miles away in warsaw i was born and was one of the most damaged city in the world and also was the most in danger because Russia was at one side and Germany at the other