HMP Magilligan is a medium security prison run by the Northern Ireland Prison Service situated near Limavady, County Londonderry. It was first opened in May 1972 and comprised eight Nissen huts on the site of an army camp. The prison was divided into compounds to house the various paramilitary factions and was manned by British Army dog handlers and prison staff on detached duty from Scotland, England and Wales as well as some staff from Northern Ireland. The temporary accommodation was later replaced by three H-blocks similar to those at the Maze prison each containing 100 cells.