Chelmek
In October 1942, a Auschwitz satellite camp was set up next to a railway in Chelmek. About 150 prisoners (mainly Jews) from Auschwitz were used as slave workers in a local shoe factory. Their job was to clean ponds from where the factory took its water. These prisoners came from France, Belgium and Holland. Hunger, hard work and beatings from SS guards were daily routine. The camp only existeed for two months but during these two months, 47 prisoners died. Another 64 prisoners were so sick they had to be moved to the Auschwitz infirmary. In late 1942, the camp was closed and the remaining 34 prisoners were sent to Auschwitz. Of these, at least 28 died within a month, which means that virtually all the camp’s prisoners died.
Current status: Demolished with monument (2015).
Location: 50° 6' 14" N 19° 16' 24" E
Get there: Car.
Follow up in books: Kogon, Eugen: The Theory and Practice of Hell: The German Concentration Camps and the System Behind Them (2006).
Considering that the camp only existed for two months, the monument looks way more lavishly than many other monuments at camps that existed much longer. Why so I don’t know, but one reason may be that it is private financiers who have financed this monument and have some kind of personal connection to the camp. But this is pure speculation.