The enclosure is C-shaped, around thirty metres across, and defined by substantial mound walls, the kind built by piling earth and stone into low, broad banks rather than raising a single upright barrier. Here and there, the tops of individual stone uprights push through the surface of those banks, hinting at the structure beneath. What makes the site quietly remarkable is not just its age but its context: this is one farmstead among three in the same valley, all of a prehistoric date, suggesting that Coolnatullagh once supported a small dispersed community of farmers rather than a single isolated household.

The enclosure sits within a wider field system, also laid out in mound walls, which would have organised the surrounding ground into workable plots. Three cairns, stone mounds associated with burial, lie in close proximity to the farmstead, and one of these has been excavated. The results place activity here firmly in the Early to Middle Bronze Age. Radiocarbon dates from a central cist, a small stone-lined grave box set into the body of the cairn, returned dates of 2460 to 2140 BC. A secondary inhumation, a later burial inserted into the same monument, produced dates of 1880 to 1610 BC. The dead, in other words, were being buried within a short walk of the living over the course of several centuries. That proximity of domestic and funerary remains in a single compact landscape gives the valley an unusually legible quality for a site of this age.