The Hay Gaol is of State significance for its rarity as one of only three surviving Hay-type gaols designed by Barnet (of these, Wentworth Gaol has also been converted to a local museum while Tamworth Gaol is still in use by the Department of Corrective Services). The Braidwood-type design of the previous colonial architect was a much more common country gaol design. The Hay Gaol Museum may be found to be of State significance as it is possibly one of only a few substantial buildings remaining statewide relating to the network of World War II Internment and prisoner of war camps in NSW.