That absence is itself notable. The OS mapped Ireland in extraordinary detail across several surveys stretching back to the 1830s, and features that escaped its surveyors entirely tend to be either very subtle or very easy to overlook from the ground. This one, approximately thirty metres across on its north-north-west to south-south-east axis, was only identified through Digital Globe aerial photography, the kind of bird's-eye scrutiny that has quietly been adding unknown sites to the archaeological record across the country.

The earthwork is defined by a ditch, with one noticeably straight side at its south-west, giving it that distinctive D-shape rather than the more typical rounded form of a rath or ringfort. An enclosure of this kind, defined by a ditch rather than a bank, could belong to any number of periods and purposes, and without excavation it is difficult to say more with confidence. What sharpens the interest slightly is its proximity to another possible feature: a ditch-barrow, a type of low circular mound surrounded by a ditch, lies around thirty metres to the south-south-east. Whether the two are related in date or function is unknown, but their nearness on ground that has clearly retained earthworks well enough to be visible from the air suggests this corner of the demesne has more going on beneath the surface than the maps have ever indicated.