Most of these early medieval enclosures, built across Ireland roughly between the fifth and twelfth centuries as defended farmsteads for a single family and their livestock, have at least a gap or causeway marking where people came and went. At Ballynafearagh in County Westmeath, no such entrance survives. There are disturbance gaps at the north and east, but these look more like damage than deliberate design, leaving the question of the original threshold unanswered.

The earthwork sits in level pasture with open views in most directions, broken only by a ridge to the west. It is oval in shape, measuring roughly 39 metres north to south and 32.5 metres east to west, and it follows a classic rath arrangement: an inner earthen bank, a fosse (a ditch dug to reinforce the bank and deter approach), and an outer bank beyond that. By the time a detailed description was made in 1980, the monument was already heavily compromised. The inner bank held up reasonably well along its northern and eastern arcs, but was low and worn on the south-west side. The outer bank had survived only at the north-west, and field fences had eaten into or entirely removed the fosse and outer bank across much of the circuit. A wide depression on the northern and north-eastern side of the fosse points to quarrying at some point, which would explain some of the more dramatic gaps. The site appears on the 1837 Ordnance Survey six-inch map as a clear oval earthwork, and again on the revised 1913 twenty-five-inch edition, by which point it was already being described as modified. Whatever changes had occurred between those two surveys are not recorded.

From the air, the site reads as a tree-lined oval set against the surrounding pasture, the ring of vegetation tracing the earthworks even where the banks themselves have been reduced or lost. That outline is often the clearest way to read a monument that has been quietly eroded by centuries of farming, fencing, and opportunistic quarrying.