Auschwitz concentration camps consisted of three main camps, where two are kept as museums today. A grim memorial of the horrendous crimes against humanity committed by the Nazis. We will not get into the sickening details here, but rather point out some (maybe surprising) observations: Auschwitz I, the first concentration camp and what became the base, was set up in some already existing military barracks in the town of Oświęcim. The camp lied, and still lies, within the town with residential and industrial areas bordering the barb-wired camps. Later, the second camp, Auschwitz II-Birkenau, was added on the other side of the railway as an extermination camp. It was here where the gassing took place. The sheer size of Birkenau is hard to grasp. When standing in front at the infamous railway gate, the camp just extends for hundreds of metres, but what you actually see is just a fraction of the whole complex as it extends into the woods at the back, where the gas chambers were located. The third camp, Auschwitz III-Monowitz, was a labour camp with factories several kilometres away from Auschwitz I and II. There is no museum at Monowitz, though some of the factory buildings and walls still stand today.