This walled prison complex, constructed of basalt in 1857 is of State significance as one of a small group of early Victorian prisons to be built outside of Melbourne. The others being Geelong (1853), Ballarat (1856) and Castlemaine (1857).
It is also of architectural significance because of its basalt construction and because it was built under the supervison of Major-General Charles Pasley, then Commissioner of Public Works. He influenced the design and supervised the construction of such public buildings as Parliament House, Victoria Barracks, Pentridge Prison, the Kew Asylum, the Customs House, the Treasury and the General Post Office.
It has Regional significance for its long use as a centre of dairy production and distribution for that area, and for its contribution to Kilmore's rare group of Basalt public buildings.