It measures roughly 67 metres from north-north-west to south-south-east and about 50 metres across, making it a substantial feature despite its near-invisibility. Along the southern, western, and north-western arc, a low earthen bank, only about 20 centimetres high and 2 metres wide, traces the boundary. Elsewhere, the enclosure announces itself only as a faint scarp, a slight drop in the ground that you might walk across without registering. The interior tilts gently toward the north-west, and marshy ground lies close to the east, with higher land rising to the south and south-east.

Enclosures of this kind are among the most common, and least understood, features of the Irish countryside. The term covers a wide range of earthworks, from heavily defended ringforts, which were enclosed farmsteads typically dating from the early medieval period, to more ambiguous oval or irregular outlines whose original function is harder to pin down. The low, unimposing bank at Doonnagore does not suggest a heavily defensive structure, and the slight scarp on the remaining portions hints at something that was never very prominent to begin with, or that has been significantly reduced over centuries of agriculture. Whether it served as a farmstead enclosure, an animal pen, or something else entirely, the surviving evidence does not say.