The earthen bank that defines it has worn down considerably over the centuries, and the southern arc has been cut through entirely by a field boundary and a laneway that post-dates 1700, leaving a gap where the enclosure once closed. What survives is a slightly raised sub-circular area, roughly 30 metres north to south and 28 metres east to west, with the ghost of a fosse, or external ditch, still faintly traceable around parts of its perimeter.

Ringforts, also known as raths, were the most common form of rural settlement in early medieval Ireland, typically consisting of a circular area enclosed by one or more earthen banks, used to protect a farmstead and its livestock. This particular example at Ballynakill retains a possible original entrance gap on its north-east side, about 3 metres wide, which would have been the controlled point of access into the enclosure. The interior itself slopes gently from south-west to north-east, and traces of cultivation ridges are still readable across its surface. Most intriguing is a low, sub-rectangular raised area at the centre, which may represent the remains of a hut or house site, a structural remnant that would once have been the focus of daily domestic life within the enclosure. A second ringfort lies approximately 275 metres to the south-east, suggesting this part of the Westmeath landscape supported a cluster of early settlement activity rather than a single isolated farmstead.