The enclosure itself is modest in scale, roughly eleven metres across, but its construction betrays a deliberate hand. The wall, built in the drystone manner without mortar, uses an inner and outer row of upright slabs packed with rubble between them, a technique that gave the structure solidity even as the mountain weather worked against it over centuries. Much of the wall has since collapsed, particularly along the southern and south-western arc, but enough survives to trace the circle clearly, and the entrance at the south-east is still legible, flanked by two upright stones that once formed a gap just over a metre and a half wide.

What makes the site genuinely curious is not the enclosure alone but the landscape it belongs to. It sits within a network of relict field boundaries, the ghostly remains of an agricultural system that once organised this high ground into workable plots. Enclosures of this kind, circular areas defined by drystone walls, are found across Ireland and can date from the early medieval period onwards, sometimes serving as animal pens, sometimes as small homestead enclosures associated with seasonal or permanent settlement. Here on Mangerton, one of the old field walls from that wider network has actually crept into the enclosure itself, its north-south line crossing through the western portion of the interior, suggesting the two features belonged to the same episode of land use, or that the site was later absorbed into an expanding system of boundaries. The relationship between them is left unresolved, which is part of what makes it worth lingering over.