This paper describes the survey of sarsen stones (grey-wether sandstones) in the Wessex counties of Dorset, Hampshire, and Wiltshire. This was conducted as a pilot exercise in the resolution of basic landscape problems through fresh investigation on the ground by a relatively large number of people in a restricted time. It sought to settle the following questions: how extensive was the surface sprawl of sarsen boulders and how, from Neolithic times, were sarsens dealt with either as an impediment or as a mineral resource? A small test excavation to see whether and how superincumbent sarsens affected the bedrock is briefly described. The massive collection of data is now kept as an archive in the Society's library at Burlington House and Xerox copies of summary lists based on this archive are available on request from the Assistant Secretary.