Roughly fourteen metres in diameter and bounded by a stone wall that is substantial in places though partially reclaimed by vegetation, it is the kind of feature that can disappear entirely at ground level, becoming legible again only when seen from above. It was aerial imagery, captured between 2011 and 2018, that brought it back into focus.

The enclosure sits within what has been identified as an extensive multiperiod field system, meaning the surrounding landscape carries traces of agricultural organisation from more than one era, the boundaries, banks, and walls of different periods overlapping and persisting in the same terrain. Circular stone enclosures of this type are found across Ireland in upland settings and are difficult to date without excavation; they may represent early medieval farmsteads, stock enclosures, or earlier forms of land management entirely. The Rannagh example was documented by Conn Herriott, who identified it through comparative analysis of satellite and aerial photography. A second possible enclosure lies roughly 85 metres to the south-east, raising the question of whether the two features formed part of a related complex rather than representing isolated incidents in the landscape.