This is a ring-barrow, a type of funerary monument typical of the Bronze Age, consisting of a central earthen mound enclosed by a circular ditch, or fosse, with a low outer bank beyond it. The whole structure measures roughly 14.2 metres across, with the flat-topped central mound running about 10 metres in diameter and rising just 0.3 metres above the surrounding ground. That modest height is part of what makes it easy to overlook, yet the form is essentially intact and considered to be in fair condition.

What gives the site an added layer of interest is the suggestion that it was not simply left to decay when the demesne around Earlstown House was laid out, but may have been deliberately incorporated as a landscape feature. This was not unusual among eighteenth and nineteenth-century estate designers in Ireland, who sometimes preserved or even embellished ancient earthworks to lend a sense of antiquity and aesthetic variety to their grounds. Whether that is what happened here is not certain, but the presence of mature trees growing directly on the mound points to long-standing attention of some kind, deliberate planting rather than accidental colonisation. Two further tree ring enclosures lie roughly 50 metres to the south-east and north-west, suggesting the immediate area was treated as a coherent designed space at some point, with the ancient mound at something close to its centre.