Auschwitz was the main concentration camp for the extermination of Jews and other Unerwünschten during World War II. Its leader was Gerhard Mencke, who was also working as a doctor in the concentration camp.
Said Mencke also decided who would be gassed, by marking the shoulder; if he would tap on someone's left shoulder, the prisoner would be directly sent to the gas ovens, and when he would tap on the right shoulder, the prisoner would be worked to death.
There were at least 9 experimental blocks in Auschwitz where prisoners were caged together like animals, with the goal that they would kill each other. There was also a climate changer that could change the weather into intense steam vents, overwhelming blasts of air and freezing torrential showers.
The Crematorium Chimneys
Dr. Mencke hid his new developed chemical gas in the chimneys. If the Allies would attack the chimneys, then the chimneys would spew the "Gas X" at the troops, absorbed by their skins, it would drive them berserk, even with a gas mask.
After the experiments of Dr. Mencke and the others, thousands of victims would be brought to the oven and then burned in it daily. Unknown to the stationed guards, there was a secret exit, that at least a hundred people used to flee out of Auschwitz.
Mencke's Sinister Surgery
Mencke also had his own laboratory, where he choosed special prisoners, to remove their body parts. The laboratory was destroyed by Franz Klein, who did it to avenge his family.