What survives at Coorleagh, in the valley of the Coomeelan stream, is a curvilinear field boundary that bobs in and out of visibility along its length, partly swallowed by peat, partly protruding above it, its course tracing a gentle meander down towards the west and north-west. It is roughly 125 metres in total extent, though only sections of it are visible at any one time, the rest submerged at or just below the bog surface.

The wall itself is modest in its surviving dimensions, around 0.7 metres thick and 0.4 metres high where it clears the ground. What gives it archaeological interest is less its scale than its shape and its situation. Curvilinear field boundaries of this kind, meaning walls that follow a curved rather than straight line, are often associated with early medieval land use in Ireland, a period when farming communities divided hill pasture into enclosures without the geometric logic that came with later land clearance and plantation. The fact that the bog has preserved it at all is a minor accident of landscape history. Blanket bog, which accumulates slowly over waterlogged ground, can seal earlier surfaces beneath it, holding walls, field systems, and even soils in place long after the people who built them are gone. Here on the rough hill pasture above the Coomeelan valley, that process has left the wall neither fully buried nor fully exposed, but suspended somewhere between the two.