Earthworks of medieval ridge and furrow, to the north-east of North Coates. Identified on an aerial photograph taken in 1971 and examined as part of the Lincolnshire Coastal Grazing Marsh project. {1} The earthworks of a probable medieval boundary was also noted on aerial photography of this area, examined as part of the National Mapping Programme. The boundary lies at the western edge of the ridge and furrow, and likely acted as a division of the open field system here. {2}