David Strachan has worked in curatorial field archaeology in Wales, England and Scotland, at both national and local level, over the last 30 years. Having established the Historic Environment Record and planning archaeology service for Perth and Kinross in 2000, as Director of Perth and Kinross Heritage Trust he maintains interests in the Scottish 'long' Iron Age, intertidal and upland archaeology, and aerial photography. David Sneddon has 20 years professional experience in archaeology, the last eight years of which were with Northlight Heritage where he was Project Manager. He recently co-founded Clyde Archaeology who provide archaeological and heritage services across the UK. Richard Tipping has worked on problems of interpreting northern British landscapes since 1984 as a palaeo-ecologist, historical geomorphologist, geo-archaeologist and environmental historian. He has authored, co-authored and edited twelve books and more than 250 peer-reviewed and other contributions.