Grini concentration camp Grini prison camp ( , ) was a Nazi concentration camp in Bærum , Norway , which operated between 1941 and May 1945 . In the present time Ila Detention and Security Prison is located here . History . Grini was originally built as a women ' s prison , near an old croft named " Ilen " ( also written " Ihlen " ) , on land bought from the Løvenskiold family by the Norwegian state . The construction of a women ' s prison started in 1938 , but despite being more or less finished in 1940 , it did not come into use for its original purpose : Nazi Germany ' s invasion of Norway on 9 April 1940 , during World War II , instead precipitated the use of the site for detention by the Nazi regime . At first , the Nazis used the prison to detain Norwegian officers captured during the Norwegian Campaign fighting . This use was discontinued in June 1940 , when Norway capitulated . The prison was then used to house Wehrmacht soldiers until a concentration camp was established on 14 June 1941 . The first detainees were sent from Åneby concentration camp , the use of which was at the same time discontinued . Shortly afterwards , the ranks of prisoners were increased by detainees captured during Operation Barbarossa . The camp was run by Schutzstaffel and Gestapo personnel , who renamed the camp " Polizeihäftlingslager Grini " . The name corresponds to a nearby farm and surrounding residential district located a short distance southeast of the camp , but historically the area at Ilen had no connection to Grini farm . At first inmates were detained on the premises of the original prison , but in 1942 an extra barracks had to be built to enlarge capacity . Grini was used primarily for Norwegian political prisoners , but the detention of more regular criminals followed . Many were held at Grini before being shipped to camps in Germany ; 3 , 402 people in total passed through the camp en route to camps in Germany itself . Similarly , many teachers who took part in the civil disobedience of 1942 were held at Grini for one day before being taken to Kirkenes via Jørstadmoen . A small number of foreign citizens were also held there . Altogether , 19 , 247 prisoners passed through Grini , and at most ( in February 1945 ) there were 6 , 208 , although not all of these actually sat at Grini at a given time . The total number killed at Grini is unknown , though the Gestapo and police often used the area for purposes of torture and at least eight people were executed there . British airborne troops sent by glider to sabotage the Norsk Hydro heavy - water plant during Operation Freshman crashed in Norway due to foul weather . The five uninjured survivors were taken prisoner and held at Grini concentration camp until 18 January 1943 , when they were taken to nearby woods , blindfolded and shot in the back of the head by the Gestapo . This was a war crime , in breach of the Geneva Convention . Executions normally took place at Akershus Fortress or Trandumskogen . Camps in other parts of Norway , including Fannrem , Kvænangen and Bardufoss , were organized as part of the Grini system . German forces also maintained a military camp at Huseby , not far from Grini . Prison life . Other than guards , the German occupiers devoted few personnel to the camp . Since many politicians , academics and cultural personalities were detained at Grini , a certain level of internal organization was established . Prisoners worked in manufacturing , agriculture and other manual labor . Much of this manual labor took place outside the camp . Some detainees maintained their pre - war specialties , such as literary historian Francis Bull who secretly held several lectures , and managed to publish three books with material written during his three - year stay at Grini . The diet at Grini was poor . After the war , it caused a certain stir in the populace when it was perceived that Nazi prisoners of the liberated Norway were treated better than prisoners of the Nazi regime ; among other things the diet in Norwegian prisons was much better . On the other hand , Grini was more hospitable to resistance prisoners than the similar camps in Germany . Liberation . On 7 May 1945 Harry Söderman , who was in charge of the education of the Norwegian police troops in Sweden , arrived in the camp and ordered commander Zeidler to arrange an assembly , first for the 5 , 000 male prisoners , and then for the 500 females . The women were released immediately , while the male detainees were asked to stay in the camp for a few days until transport could be arranged , and leadership of the camp was handed over to the prisoners ' representatives . Prisoners from Møllergata 19 and Victoria Terrasse were transferred to Grini the same day . After the war . After the liberation of Norway in May 1945 , the prison was used for Norwegians tried or convicted of treason or collaboration , as a part of the legal purge in Norway after World War II . Since the name " Grini " was now associated with the Norwegian resistance movement , hence seen as heroic , the camp was renamed Ilebu . The new name also reflected the actual location of the camp better . 3 , 440 people were imprisoned here in July 1945 . The conditions in the camp were unhealthy , with beri - beri breaking out in the summer . A guard reported that punitive exercise was used in a harsh way . on 13 October 1945 the National Mobile Police Service performed a razzia ( police raid ) . During the razzia , prosecutor Lauritz Jenssen Dorenfeldt and the wife of camp director Helge Gleditsch were wrongly rounded up in the yard . It was closed in 1951 but reopened in the same year under the name Ila as a " landsfengsel og sikringsanstalt " ( national prison and security institution ) , a prison for criminals serving long - term sentences . Much of the camp , including the barracks , has been torn down . One preserved barracks building today stands at Kadettangen . There is also a museum , the Grini Museum , near today ' s Ila prison . The preserved barracks was moved back in 2010 . Printed documentation . Architect Odd Nansen managed to preserve most of his diaries from Grini and Sachsenhausen , and selections from these were issued in 1946 as the three - volume book " Fra dag til dag " ( " From Day to Day " ) . Volume one covers the period from January 1942 to August 1942 , volume two covers August 1942 to August 1943 , and volume three covers Nansen ' s stay in Sachsenhausen . In 1946 and 1947 the two - volume book " Griniboken " ( " The Grini Book " ) was issued , edited by August Lange and Johan Schreiner , with contributions from several of the detainees . The first volume describes daily life at Grini as it developed over the years , including separate articles on the women ' s department , on the " Haft " departments ( for men and women ) , and on " Fallskjermen " , the department for those who were sentenced to death and awaiting execution . The second volume covers the internal organisation , such as the labor , farm work , and healthcare regimes , in more detail , and also discusses cultural and religious life . The external locations ( Kvænangen , Kongsvinger , Bardufoss , and others ) are described . There are also chapters on the undercover resistance at Grini , such as the news service , espionage , and the secret finger - signing language which was developed . Børre R . Giertsen ' s 1946 book " Norsk fangeleksikon . Grinifangene " ( " Norwegian Prisoner Encyclopedia : the Grini Prisoners " ) contains an overview of the German staff at Grini , as well as a chronologically ordered list of the prisoners , starting with the Solvær hostages incarcerated at Åneby 15 March 1941 .