Sunghori concentration camp

The Sŭnghori concentration camp was a labor camp for political prisoners which is said to have existed in North Korea, about 70 kilometers from Pyongyang. 
Little is known about it as its inmates were considered 'irredeemables' and never released. Senghori is described by North Korean refugees and defectors as one of North Korea's most feared labor camps, where inmates live and work in terrible conditions. Kang Chol-hwan described it as a "camp of no return." Prisoners, including Kang's grandfather, who were sent there, would almost never be released. Kang did meet one prisoner who was transferred to his own camp, who described Sŭnghori prisoners being worked as coal miners. According to Kang, the camp was closed after a report by Amnesty International.