Most raths, the circular earthwork enclosures built across Ireland primarily during the early medieval period as farmsteads and defended homesteads, were recorded by the nineteenth-century surveyors even when they were little more than a grassy ring in a field. This one at Alderford was missed entirely, and its existence only became apparent through aerial photography, where it shows up as a clear circular feature on the summit of a north-west to south-east ridge.

The rath is a roughly circular grass-covered platform, measuring approximately 35.6 metres across on its north-north-west to south-south-east axis and about 33 metres on the other. It is defined by a scarp, essentially a slope or drop in the ground surface, standing between 1.5 and 1.65 metres high. Beyond that, to the north-east and east-south-east, there is a slight fosse, a shallow external ditch around six metres wide but only about ten centimetres deep, which survives as a wet, boggy area to the north-west and north. No original entrance can be identified. The monument was at some point planted with trees, which have since been removed, and a north-west to south-east avenue now runs directly across it, further complicating any reading of the original ground plan.

Because the rath sits on a ridge summit and was never mapped, it occupies an odd position: physically prominent in the landscape, yet administratively invisible for well over a century. The avenue and the tree planting suggest it was absorbed into a designed estate or demesne landscape at some point, the earthwork treated as a convenient piece of elevated ground rather than recognised as something considerably older.