The Old Government House buildings reflect how the wealthy of the Victorian era lived, with the Main House displaying the style and accoutrements of the well-to-do and the Servant’s Quarters are the more modest furnishings of a working family. It was the summer residence of the Governor of South Australia from 1860-1880, and was used by governors Richard Graves MacDonnell (1855–62), Dominick Daly (1862-68), James Fergusson (1869-1872) Anthony Musgrave (1873-1877) and William Jervois (1877–80). Old Government House was South Australia’s first official vice-regal summer residence. It was constructed from local sandstone, with the red-brick for the quoins sourced from the Blackwood brick-works, and a native timber shingle roof.  The residence’s indoor plunge-pool was reportedly the first in the colony.

Old Government House was superseded by a larger summer residence at Marble Hill, completed in 1880. OGH was then used by the curator of the Department of Woods and Forests Nursery (also located in Belair National Park) until it was transferred to the National Parks and Wildlife Reserves in 1961. Minor renovation work was carried out and the building was opened as a museum. More extensive renovations in the 1970s and again in 2002-03 restored the building to its original grandeur.

The buildings are surrounded by a garden of approximately one acre. At the time of the Governors, the garden was natural bush land surrounded by a post and rail fence. Today it has been re-designed as a mid-Victorian garden of Anglo-Italian style to complement the restored complex.