Trim Gaol was constructed c1832 and adopted the Panopticon design which provided for a radial or polygonal arc of cell blocks encircling a central inspection block where the governor could more easily monitor the prisoners and his staff and ensure a balanced and fair system of justice. Walled exercise yards filled the external spaces between the radiating cell blocks. The Panopticon system was developed and advocated by the English philosopher, social theorist and political economist Jeremy Bentham (1747-1832) who described his design form “as a machine to grind rogues honest”.

The gaol was demolished in the 1950’s with the site later used for the construction of Scoil Mhuire secondary school which still occupies the site. The original northern entrance screen wall was retained, acting as a 96m long by 8.5m high boundary wall to the OPW lands to the north of the site.

Conservation and consolidation works including repointing, stone consolidation and weathering & re-setting of parapet wall tops were carried out in three phases during the summers of 2020-2022 with Greg Smith Conservation acting as principal contractor. The southern face of the wall which originally was an internal face to lean-to structures within the prison compound (and as such was more vulnerable) required more intensive repair works than the partly rusticated cut-stone external northern wall face.