An oval earthwork or platform, roughly 22 metres across, was recorded as an antiquity as far back as the 1837 Ordnance Survey six-inch map, and that oval shape persisted across subsequent editions of the same mapping series. But when the site is examined through more recent aerial imagery, the feature appears not as an oval at all, but as a roughly square-shaped earthwork. The ground itself, or at least our reading of it, seems to have changed form across the centuries.

The 1837 Ordnance Survey maps were among the most systematic and detailed cartographic exercises ever undertaken in Ireland, and when surveyors of that era marked something specifically as an antiquity, it was a deliberate act of recognition, a signal that the feature pre-dated their own time and merited note. The Reynella earthwork earned that designation, which places it in a long lineage of low-profile but significant landscape features that have quietly outlasted the societies that built them. Adding further context is the presence of a ringfort, a type of enclosed farmstead typical of early medieval Ireland, lying just 75 metres to the north-east. The proximity of the two features suggests this corner of County Westmeath may have held some sustained significance across time, though precisely what relationship, if any, existed between the earthwork and the ringfort remains open to interpretation.