The building was one of the oldest political prisons in Iran, which is now a museum complex surrounded by a public park.
[2] For Mohammad Reza Shah, it served as a torture and execution chamber for extreme political crimes which by the late 1970s was extensively reformed by the Red Cross into what was described a "hotel" by the staff.
[2] Following the 1979 Revolution, many civil and military officials of Mohammad Reza Pahlavi were detained and executed at the prison, including Nader Jahanbani and Amir Hossein Rabi'i;[3] Major General Manuchechr Khosrodad[4] and Prime Minister Amir Abbas Hoveida[5][6] were imprisoned at Qasr before being executed on the roof of Refah School, where Khomeini had set up his headquarters.
[2] In subsequent decades the prison fell into disuse till in 2005 it was announced by the ICHTO that the compound would become a museum.
According to the Iranian Students News Agency Qasr was named the most creative museum in the country in 2013.