This D-shaped enclosure, measuring roughly 81.5 metres northeast to southwest and 41.5 metres northwest to southeast, is defined by a curving scarp and external fosse on its southwestern side, whilst a modern field wall marks its southeastern boundary. The defensive ditch and bank system remains well-preserved in places, particularly along the northern and northeastern sections, though time and agricultural use have taken their toll; the fosse has been repurposed as a field drain at the southwestern end, and a septic tank now occupies part of the northwestern section where the original entrance likely stood.

Within this enigmatic earthwork lie two distinct platforms that hint at its possible medieval origins. At the northeastern end, a sub-rectangular platform approximately 16.5 by 10.6 metres appears to have been created by scarping a natural rise, complete with a raised stony rim along its northern edge that stands nearly two metres high externally. This elevated position may have served a motte-like defensive function, though quarrying has damaged its western side. The southern half of the interior contains an oval platform that later served as a children’s burial ground, first noted on the 1920 Ordnance Survey map and recorded by Knox in the early twentieth century.

The earthwork’s strategic positioning is no accident; it occupies low-lying ground with natural wetland defences to the east, whilst maintaining a clear view of Brees Castle, the later masonry fortification that sits prominently on a ridge just 300 metres to the southeast. This spatial relationship suggests the earthwork may have been an earlier ringwork castle, possibly marking the initial Anglo-Norman foothold in the area before the construction of the more substantial stone castle on higher ground. Though not marked on the 1838 Ordnance Survey map, this overlooked monument offers a tangible link to the complex patterns of medieval settlement and fortification that shaped the Irish landscape.