The New Gaol at Montgomery was designed by the Oswestry architect Thomas Penson and constructed in the 1830s to replace the prison on Castle Hill. It was closed in 1878, but the gatehouse, built in 1866 (NPRN 32034), governor's house (NPRN 29266) and warder's house (Oakfield Cottage, NPRN 29662) still survive. A cellblock wall to the north of the governor's house survived until the 1980s. Much of the stone from the gaol was used to build the nearby house called Plas Offa.
RCAHMW, 19 November 2007.