GEORGE NASH is an Associate Professor at Geosciences Centre of Coimbra University (u. ID73-FCT), Polytechnic Institute of Tomar (IPT), Portugal. Dr Nash is a specialist in openair rock art and contemporary street art and has recently undertaken fieldwork and research in Andean Chile, the Negev Desert in southern Israel, central Portugal and Wales. | ARON MAZEL is a Reader in Heritage Studies at Newcastle University, United Kingdom. Dr Mazel has done extensive recording of rock art in the uKhahlamba-Drakensberg (South Africa) and Northumberland (United Kingdom).