The University of the Witwatersrand houses two provincial heritage sites and two heritage objects. The Great Hall (technically the façade of the Robert Sobukwe Building, formerly known as Central Block, in which the Great Hall is located), and the Dias Cross housed in the William Cullen Library are both provincial heritage sites. They were formerly national monuments, until 1 April 2000 when the National Monuments Council was replaced by a new system which made former national monuments the responsibility of provincial governments following the passage of the National Heritage Resources Act. The heritage objects are Jan Smuts' study, housed in Jan Smuts House, and the Paul Loewenstein Collection of rock art. All of the university's national heritage sites and objects are located on East Campus.