It appears on neither the 1838 nor the 1922 Ordnance Survey six-inch maps, which means that for the better part of two centuries of systematic Irish cartography, whatever remains here simply went unrecorded. That absence is itself curious, because the site is reasonably substantial, roughly thirty-eight metres east to west and up to thirty-seven metres north to south, occupying a subcircular area on pasture land about a hundred and fifty metres from the rocky shoreline and Trabaun beach.

The structure is poorly preserved, and its original form is genuinely difficult to read. What survives is a low, sod-covered stony bank along the north-northwest to southwest arc, spread to between three and five metres wide but rising only marginally above the surrounding ground, with a less clearly defined inward-facing scarp along the western side. An enclosure of this type, a roughly circular or subcircular area bounded by a bank or earthwork, is a common enough form in the Irish landscape, related to the broader family of enclosed settlements that includes ringforts, which are farmsteads typically dating from the early medieval period, roughly the fifth to the twelfth centuries. Whether this example belongs to that tradition is unclear; the poor preservation means its function and date remain open questions. A gap of seven metres in the bank at the east-northeast may represent an original entrance, or simply a later breach. The interior has been further disturbed by quarrying, which has left a semi-circular depression immediately north of a later field wall that cuts across the site, and a heap of clearance stone has been piled onto the southern bank at some point. About a hundred metres to the northwest, a separate ringfort survives, suggesting that this small corner of Castlenageeha has a longer pattern of human use than its unremarkable present appearance might suggest.