Three of its walls survive to some degree; the fourth was lost when a modern fence was built across its line, erasing whatever evidence that side might have offered. It is the kind of structure that rewards careful looking rather than a quick glance, its remaining walls barely reaching knee height in places, yet clearly the product of considered construction.

The enclosure was recorded by O'Kelly in 1944, who noted that the north and east walls were built from large, carefully placed limestone blocks, while the south side had been reduced to an earthen bank. At that time the walls still stood to roughly three feet, or just under a metre. The overall dimensions, twenty metres by just under thirteen, suggest something more substantial than a casual field boundary. O'Kelly observed that no entrance could be recognised, which complicates any straightforward interpretation. An enclosure is a broad category in Irish archaeology, referring simply to a defined space bounded by walls, banks, or ditches; it can apply to anything from a farmstead to a ceremonial site, and without more detailed excavation or documentary evidence, the function of this particular example remains open. An aerial photograph taken by the Archaeological Survey of Ireland in September 2002 was attached to the site record when it was compiled by Caimin O'Brien in 2019, and may offer a clearer sense of the structure's footprint from above than is easily gained on the ground.

Knockainy itself is a hill with considerable archaeological and folkloric associations in County Limerick, so the enclosure sits within a landscape that has attracted human activity across many centuries. The site is on the southern slope, which means it would have had reasonable shelter and some elevation over the surrounding terrain. There is no formal access point recorded for the enclosure, and the surviving fabric is low enough that it could be easily missed without a grid reference to hand. Visiting in late autumn or winter, when vegetation dies back, gives the best chance of making out the wall lines, particularly the limestone coursework on the north and east sides that O'Kelly singled out for its careful construction.