A modern field wall cuts straight through its centre on an east-to-west axis, a tractor gap has been opened in the eastern bank, and the southern rampart has been pressed into service as a field boundary, topped with a low stone wall. The site has been absorbed, incrementally, into the working farm around it. What gives it away is the geometry: a roughly circular enclosure measuring about 37.8 metres east to west and 35 metres north to south, its banks still holding a height of over a metre in places, ringed by hawthorn and slowly being reclaimed by spreading brambles.

This is a rath, the Irish term for a ringfort, the most common monument type surviving in the Irish countryside. Raths were typically built during the early medieval period, roughly between the fifth and twelfth centuries, and served as enclosed farmsteads for a single family or small household. The enclosing bank, often accompanied by a ditch on the outside, defined both a physical and a social boundary. At Ballynamona, the northern half of the enclosure survives as a dilapidated bank and scarp, while the southern half retains a more substantial earth and stone bank roughly two metres wide. Large boulders have been piled along the scarp over the years, almost certainly the result of field clearance from the surrounding pasture rather than any original construction. At the north-east, a low break in the scarp is flanked on either side by an upright slab, which may mark the original entrance to the enclosure. Near the centre of the interior, partly hidden beneath long grass and cut through by the field wall, is a low circular rise with a slightly hollow centre, about six or seven metres across, the function of which is not recorded but which adds a further layer of interest to an already layered site. The Trimoge River runs roughly 400 metres to the north-east, and the elevated position gives wide views across a gently rolling landscape of rough pasture and wet ground, the kind of setting that would have made sound practical sense to an early medieval farmer choosing where to build.