What makes it quietly peculiar is the disagreement it has generated, not only about its age and purpose, but about something as basic as its size. An early survey attributed to Westropp recorded dimensions of roughly 33 by 38 metres, implying an oval shape, yet O'Kelly's 1944 reassessment found the monument to be circular with an overall diameter closer to 58 metres, a significant discrepancy that changes how one reads the whole structure.

A ringfort, or rath, is an enclosed farmstead or settlement site typically dating from the early medieval period, defined by one or more earthen banks and an outer ditch, or fosse, dug to heighten the bank's apparent scale. This example has a fosse averaging eight metres wide, and the causewayed gap on the eastern side, where the ditch is bridged by an uncut section of ground, marks what appears to be the original entrance. O'Kelly noted a maximum height of about 4.5 metres from fosse-bottom to bank-top, which is a substantial figure. The western half has been partially levelled over time. Westropp, working with what O'Kelly later judged to be insufficient evidence, proposed that the site might be identified with the Síd of Eoghabal, a fairy mound from Irish mythology associated with the goddess Áine, or alternatively with Dún Cliach, a fort said to have been repaired by Brian Boru. A 2004 survey by Condit and Coyne added a further complication, suggesting that the size and proportions of the earthwork are more consistent with a medieval ringwork, a type of fortification associated with the Norman period, than with a typical early medieval rath.

The monument crowns the summit of the western side of Knockainy hill and is visible from some distance, though the interior is largely featureless, with a modern field boundary crossing it. The bank is composed of a mixture of earth and stone. Aerial photographs held by the Archaeological Survey of Ireland, taken in 2002 and 2003, give the clearest sense of its overall shape and the relationship between the bank, the ditch, and the causewayed entrance to the east. Anyone approaching on foot should look for that eastern causeway as the clearest surviving indicator of the monument's original design.