Satellite photographs, such as the CORONA series, are proving valuable instruments of archaeological reconnaissance, especially for landscapes that are relatively unknown or unprotected. Moreover, satellite imagery can be used for detailed mapping of remote areas, so that a topographic map or Digital Elevation Model can form the background for the archaeological information. However, images seen on the photographs may not be immediately recognisable as sites, and sites on the ground may escape detection from a satellite. In a current project in south Siberia the authors test the visibility of the one against the other.