The largest of the three is roughly 25 metres in internal diameter, defined by a double-kerbed wall with a rubble core, meaning two lines of upright or carefully placed stones sandwich a fill of loose rock between them, a construction method that suggests deliberate, if not elaborate, effort. Just seven metres to the west sits a slightly smaller companion enclosure, around 18 metres across, and a third lies approximately 47 metres to the south-west.

Mooghaun itself is one of the largest hillforts in Ireland, a site of considerable complexity with multiple concentric ramparts enclosing the high ground above the Shannon estuary. The enclosures described here sit outside the middle rampart, in the north-west quadrant, which places them in a liminal zone, neither fully inside the defended interior nor entirely detached from it. Researchers Tom Condit and Eoin Grogan, writing in 2005, proposed a middle to late Bronze Age date for these enclosures, roughly somewhere between 1500 and 700 BC, drawing the comparison to similar structures identified elsewhere in the region. Whether they served as settlements, stock enclosures, or had some ceremonial function remains unresolved, but their grouping and their position relative to the hillfort make them part of a broader, layered landscape of prehistoric use rather than isolated curiosities.