Cartographers mapping Ireland in 1841 recorded it not as the oval enclosure it actually is, but as a rectangular feature, raising the possibility that what survives today may be only part of a more complex, or differently shaped, original structure. Barry, writing in 1981, went further, listing it as a possible moated site, which would place it in an entirely different historical category from the typical early medieval rath.

A rath, or ringfort, was the commonplace farmstead of early medieval Ireland, typically a roughly circular area enclosed by one or more earthen banks with an external ditch, used to protect a family and their livestock. A moated site, by contrast, was a later medieval form, generally rectangular, surrounded by a water-filled ditch, and associated with Anglo-Norman settlement from the twelfth century onwards. That a single site in County Limerick should attract both labels is not a contradiction so much as a reflection of how eroded and ambiguous these earthworks can become over time. The enclosure at Ballynamona measures approximately 34 metres north to south and 38 metres east to west. Its earthen bank survives to an internal height of roughly 0.3 metres and an external height of 0.35 metres, dimensions that suggest considerable slighting over the centuries. The southern arc is the best-preserved section; along the western edge, a former field boundary was laid directly over the bank and has since been removed, leaving that portion of the monument faded almost to nothing.

The site sits atop a low rise in gently undulating pasture, and the interior dips slightly towards the centre, with limestone outcropping in places beneath the grass. That combination of subtle topography and exposed bedrock gives the interior a particular character once you are standing inside it. There is no formal access or signage, and the monument blends easily into the surrounding farmland, so careful attention to the landscape is necessary. The southern arc, where the bank is most legible, is the logical place to begin reading the site. Because the earthworks are so low, overcast conditions or low-angle winter light can actually help make the bank's profile more visible against the pasture.