Within the Simpson people go to see the ruins at Dalhousie Springs , Purnie Bore wetlands , Approdinna Attora Knoll and Poeppel Corner ( where Queensland , South Australia and Northern Territory meet ) . The desert is popular with tourists , particularly in winter , and popular landmarks include the ruins and mound springs at Dalhousie Springs , Purnie Bore wetlands , Approdinna Attora Knoll and Poeppel Corner ( where Queensland , South Australia and Northern Territory meet ) .