Kemna concentration camp was one of the early Nazi concentration camps, created by the Third Reich to incarcerate their political opponents after the Nazi Party first seized power in 1933. The camp was established in a former factory on the Wupper river in the Kemna neighborhood of the Barmen quarter of Wuppertal. It was run by the SA group in Düsseldorf.
The purpose of the early concentration camps was to repress and terrorize opponents of the new regime, primarily communists, but also socialists, dissenting Christians, and trade unionists. Unlike later concentration camps, the prisoners and the guards at Kemna were from the same cities and in many cases, knew each other and were already enemies from the German Revolution of 1918–1919 and subsequent political battles of the 1920s.
Wikipedia https://en.wikipedia.org/wiki/Kemna_concentration_camp
Address 164 Beyenburger Straße, Wuppertal 42287, Germany
Coordinates 51°15'20.876" N 7°15'19.323" E