Mittelbau - Dora Mittelbau - Dora ( also Dora - Mittelbau and Nordhausen - Dora ) was a subcamp of Buchenwald concentration camp in Nazi Germany . Its prisoners were used by the SS mainly in the tunnel excavation and nearby underground stations of the Mittelwerk Ltd . , in Kohnstein , situated near Nordhausen , where the V - 2 rocket and the flying bomb V - 1 rocket was produced . During 18 months about 60 , 000 prisoners from 21 nations passed through Dora . An estimated 20 , 000 inmates died ; 9000 died from exhaustion and collapse , 350 hanged ( including 200 for sabotage ) , the remainder died mainly from disease and starvation . The subcamps of Konzentrationslager Mittelbau ( Concentration Camp Central Construction ) eventually totalled more than 40 . Operation . Following Hitler ' s 22 August 1943 order for Heinrich Himmler to use concentration camp workers for A - 4 production , 107 inmates arrived at Nordhausen from Buchenwald on 28 August 1943 , followed by 1 , 223 on 2 September . Peenemünde workers departed for Dora on 13 October 1943 . Originally called Block 17 / 3 Buchenwald , the SS administration ordered Dora to be politically separated from Buchenwald at the end of September 1944 and to become the center of Konzentrationslager Mittelbau . In effect , the camp became operational on 1 November 1944 with 32 , 471 prisoners . Tunnels in the Kohnstein were used as quarters until workers completed the Dora camp on 31 December 1943 , less than a kilometre from the tunnel B entrance to the South . The camp had 58 barracks buildings and the underground detainee accommodations ( " sleeping tunnels " ) were dismantled in May 1944 . Official visits included a 10 December 1943 visit to Dora by Albert Speer , and Wernher von Braun visited the Nordhausen plant on 25 January 1944 . Von Braun returned for a 6 May 1944 , meeting with Walter Dornberger and Rudolph where Albin Sawatzki discussed the need to enslave 1 , 800 more skilled French workers . Dora conditions . Most of the inmates of the camp were men , but a few women were also held there , as well as in its sub camp Groß Werther . There was one known female guard Lagerführerin Erna Petermann . The prisoners were subject to extreme cruelty . As a result they often suffered injuries , including permament disability and disfigurment , and death . Severe beatings were routine , as was deliberate starvation , torture and summary executions . Between January and February 1944 , approximately 2 , 000 of the most sick and disabled prisoners were transferred to the Majdanek concentration camp in German occupied Poland where they were murdered . The SS used the Boelcke Kaserne , a former barracks in the town of Nordhausen , as a dumping ground for hopeless prisoner cases . On the night of 2 April 1945 , Royal Air Force bombers burned down much of Nordhausen in two nighttime fire raids , killing 1 , 500 sick prisoners at Boelcke Kaserne . On 3 April 1945 , prisoners began leaving Dora to the Harzungen sub - camp about around the hill of Kohnstein . Liberation and post war . Private John M . Galione of the 104th Timberwolf Army Infantry Division discovered Mittelbau Dora on 10 April 1945 , and broke into the camp with the help of two other soldiers before sunrise on 11 April . Galione then radioed the Third Armored Division and various 104th Division attachments , giving them directions to the camp . The medics of the 3rd Armored Division ( United States ) reported that they discovered Nordhausen Camp on the way to Camp Dora ( Dora and Nordhausen are two separate camps within the same complex ) . Lying in both camps were about 5 , 000 corpses . Over 1 , 200 patients were evacuated , with 15 dying en route to the hospital area and 300 subsequently dying of malnutrition . Andrae Trial . Following the June 1945 Fedden Mission investigation of the Dora conditions , " The United States of America versus Arthur Kurt Andrae et al . " trial commenced on 7 August 1947 at the Dachau internment camp against the following defendants : The trial convicted fifteen Dora SS guards and Kapos ( one was executed ) . The trial also addressed the question of liability of Nordhausen scientists — Georg Rickhey was acquitted and Arthur Rudolph of the Mittelwerk ( recruited in 1945 under Operation Paperclip and then exiled from the US in 1984 ) was not even charged . A related trial was also held 1959 – 1961 in Essen . Mittelbau - Dora Concentration Camp Memorial . The Mittelbau - Dora Concentration Camp Memorial uses the former crematorium building ( one of the two buildings still intact ) as a museum . In 1970 the muster ground was restored and an administration building erected . The tunnel entrances were closed in 1947 using explosives ; a new entrance was cut in 1995 , allowing visitors to tour the tunnel areas .