HM Prison Pentridge was an Australian prison built in 1850 in Coburg, Victoria. The first prisoners arrived in 1851. The prison officially closed on 1 May 1997.Pentridge was often known by the nickname "The Bluestone College", "Coburg College" or the "College of Knowledge". The grounds were originally landscaped by renowned landscape gardener Hugh Linaker. Since decommissioning, the prison has been partly demolished to make way for a housing development.