At Ballysallagh in County Westmeath, an earthwork once significant enough to be formally recorded has left no trace that aerial photography can detect. Satellite imagery taken between 2011 and 2013 shows nothing but a field marked by cultivation ridges running north to south and east to west, the kind of parallel furrows left by repeated ploughing over generations.

Those ridges are themselves a clue. Prolonged tillage is one of the most effective ways to level and obscure earthworks, gradually cutting down banks, filling ditches, and redistributing soil until whatever once rose or sank into the landscape is indistinguishable from the surrounding ground. Whatever form this earthwork originally took, whether a ringfort boundary, an enclosure bank, or something earlier still, the field has been worked until the monument exists now only as a map reference and a category. No paper archive accompanied the site, which means even the minimum of administrative documentation that usually anchors such a record is missing here.