Sitting on a low-domed hilltop roughly 7.5 kilometres south of Limerick City, the enclosure at Friarstown presents a nearly circular form, measuring around 112 metres north to south and 110 metres across the northeast to southwest axis, with a total footprint of about 1.5 hectares. It is defined by a scarped inner edge, an outer earthen bank, and a flat-bottomed fosse, the term for a ditch, running between them. The interior slopes gently upward from all sides toward the summit, giving the whole arrangement an oddly theatrical quality, as though the hill itself was shaped to draw attention inward.

The monument was first identified not by someone walking the land but from the air, when the Cambridge University Committee for Aerial Photography captured its outline on oblique photographs taken in July 1968. Researchers Kelly and Condit visited the site in 1998 and partly recorded its enclosing elements, concluding that it was one of two monuments in the area best interpreted as henges, a henge being a roughly circular earthwork enclosure typically associated with prehistoric ceremonial activity rather than defence. The nearby cashel, a type of stone-walled ringfort, has since truncated part of the enclosure to the southeast, adding another layer of history to an already complicated site. However, the Atlas of Hillforts of Britain and Ireland takes a different view, arguing that the commanding elevated position and the arrangement of banks and ditch, including what appears to be a counterscarp bank on the outer edge, point more convincingly toward a hillfort. A second such enclosure sits immediately to the northeast on a lower shoulder of the same hill, which only deepens the puzzle.

The southern and western portions of the earthworks have been absorbed into forestry, so the clearest surviving sections are those to the southeast and southwest within the wooded area, where dry-stone construction is still visible beneath the bank material. Elsewhere, the enclosing elements have been considerably worn down by ploughing over the centuries. There are no obvious entrance features to guide the eye, and no surface traces of internal structures. Visitors should expect an unspectacular but genuinely curious landscape, one where the ground underfoot is the main object of attention rather than any upstanding monument.