Outgrowing available space at its buildings in town, the museum's headquarters were moved in 1973 to the former Kimberley Sanatorium (built in 1897), which at one time served also as the Hotel Belgrave (1908–1933) and as the Holy Family Convent School, Kimberley (1933–1971). The new museum headquarters were officially opened on 22 November 1976. For the duration of the Siege of Kimberley (14 October 1899 – 15 February 1900) during the Anglo-Boer War, Cecil John Rhodes lodged in rooms at what was then the Sanatorium.