A radio telescope with a collection area of 1 square km would improve ten-fold the sensitivity of current telescope technology. Such a telescope will require a 50 km diameter 'radio quiet zone'. The tools and techniques of Geographic Information Systems (GIS) and spatial analysis are used to model a series of criteria that determine an optimum location for the telescope site in South Australia. The simple combination of these criteria rates every 5-km square within South Australia for its suitability as the central site of the telescope facility. The results are shown in easily readable map form. This investigation identifies five potential sites across South Australia that are recommended for more detailed study. The identified sites are: near Coober Pedy, Marree, Lake Frome, Tarcoola and Yunta. Large areas of these sites passed all of the criteria used in this site selection study.