The Hay Gaol is of State significance for its aesthetic, rarity and representative values as an example of James Barnet's Hay-type gaol design, and as an example of a Victorian-era country prison that combines foreboding design features (such as its entranceway, perimeter walls, cell block and isolation cell) with vernacular materials. It is furthermore of State significance for its variety of historical functions, associations and social values as a small-scale prison and detention centre. Built as a colonial gaol in 1880 it was later used as a detention and hospitalisation facility servicing Hay's World War II internment and prisoner of war camps (1940 - 1946) and then as a girls' institution run by the NSW Department of Child Welfare (1961 - 1974). Although official records remain unavailable, it is believed that a significant proportion of girls sent to Hay were indigenous "Stolen Generation" children and many survivors from this era have begun visiting the site from all over Australia. It is probably the only building in Australia directly associated with the internment of the Dunera Boys and with the imprisonment of the Japanese prisoners of war (POWs) following the Cowra Breakout in 1944. The Hay Gaol is also of State significance for its research, archaeological and interpretive potential as a site or landscape of segregation, which capitalised on the already isolated geographic position of Hay to provide different forms of incarceration in different periods of history.