Whatever was once built or banked up on that rise has been levelled so thoroughly that nothing remains above the surface. The site would be entirely unknown were it not for a faint cropmark, a ghostly outline left by differential growth in crops above buried features, caught in a Digital Globe orthoimage taken sometime between 2011 and 2013. The mark is faint, but it is there, and it is enough to confirm that something deliberate once occupied this hilltop position.

Cropmarks form when buried ditches, walls, or banks affect the soil's ability to retain moisture and nutrients. Crops growing above a filled-in ditch tend to grow taller and greener; those above a buried wall or compacted surface tend to be stunted. Seen from the air or picked up in satellite imagery, the pattern can trace the outline of structures that have long since disappeared at ground level. In this case, the feature at Ballysallagh belongs to a broader category of earthworks, which might encompass anything from a prehistoric enclosure to a medieval ringfort or field boundary, though no further detail about its character or age has been established. The hillock setting is telling in a general sense, elevated ground having been favoured across many periods for enclosures and defended sites, but without excavation or closer analysis, the earthwork remains defined almost entirely by its absence.