> Can anyone tell me at which website I can download a DEM (Gauteng, South > Africa) which can be interpreted by GRASS 6? Try SRTM (r.in.srtm) or GTOPO30 (r.in.gdal) data sets. http://www2.jpl.nasa.gov/srtm/ http://edcdaac.usgs.gov/gtopo30/gtopo30.asp Hamish