Acknowledgements
This work is carried out in conjunction with Built Heritage: Northern Ireland Environment Agency (NIEA), Department of the Environment (Northern Ireland). Special thanks to Brian Williams, Rhonda Robinson, Lorraine Bourke, Liam McQuillan and Helen Murphy of Built Heritage for assistance and guidance; Michael McLean (Rivers Agency) and Sally Cook (University of Ulster) for providing digital data and Attila Tóth (National Office of Cultural Heritage, Hungary) for advice and instruction in valid field techniques. And thanks to all my colleagues at the CMA for ongoing support.