The rath at Ballynafearagh in County Westmeath survives as barely more than a suggestion in the landscape, a low earthen bank and a fosse so shallow it is difficult to read from most angles. A fosse is simply a defensive ditch, the soil from which was typically thrown inward to build the enclosing bank, and here both elements have been worn to the point where the ground seems to hesitate rather than assert any clear boundary. Only from the northeast to the south and around to the northwest does the fosse remain legible at all; from the northwest around through north to northeast it has silted and settled completely flat.

When surveyors recorded the site in 1971, they noted a circular enclosure roughly twenty metres in diameter, with traces of a second, outer bank beyond the fosse, though these outer traces were already faint by then. What also caught their attention was the interior, which carries a gentle slope facing northeast and retains the ghost of old cultivation ridges running east to west. Those ridges suggest the enclosed space was at some point turned over to small-scale tillage, which is not unusual for ringforts that had long since lost whatever domestic or agricultural function they originally served during the early medieval period. The fort sits on a very slight rise in wet pasture, with open views stretching north, southwest, and west, though a higher ground to the northeast and east overlooks it in return, which may explain why the fosse reads most clearly from those directions where any approaching eye would naturally fall.