NKVD special camp Nr. 7 was a NKVD special camp that operated in Weesow until August 1945 and in Sachsenhausen from August 1945 until the spring of 1950. It was used by the Soviet occupying forces to detain political prisoners.
In August 1945, the Special Camp Nr. 7 was moved to Sachsenhausen, the area of the former Nazi Sachsenhausen concentration camp. Under the NKVD, Nazi functionaries were held in the camp, as were political prisoners and inmates sentenced by the Soviet Military Tribunal. By 1948, Sachsenhausen, now renamed Special Camp No. 1, was the largest of three special camps in the Soviet occupation zone. The 60,000 people interned over five years included 6,000 German officers transferred from Western Allied camps. Others were Nazi functionaries, anti-Communists and Russians, including Nazi collaborators.
Wikipedia https://en.wikipedia.org/wiki/NKVD_special_camp_Nr._7
Address Walther-Rathenau-Straße, Oranienburg 16515, Germany
Coordinates 52°46'10.011" N 13°15'33.141" E