Roughly fifteen metres across at its longest and eight metres wide, the enclosure is defined by a grassed-over stone wall, the kind of feature that reads more clearly from aerial photography than from ground level, where centuries of grass and soil have softened its edges almost to invisibility.

The enclosure sits within what surveyors classify as a multiperiod field system, meaning the landscape around it preserves traces of agricultural organisation from more than one era, layers of human activity compressed into the same ground. Within the enclosure itself, tucked toward the northern interior, is a hut site, the remnant of a small structure that would once have provided shelter for a person or a family working this upland terrain. These kinds of oval enclosures, often found on higher ground across the west of Ireland, tend to be associated with seasonal pastoral farming, where people moved livestock to summer grazing on the hills and lived temporarily in simple stone-built shelters. The enclosure at Slievenaglasha follows the same basic pattern, though its precise date remains unassigned. What is clear from aerial imagery captured between 2011 and 2018 is that both the enclosure wall and the hut site within it are still legible from above, even where they have become nearly invisible underfoot.