What looks, from a distance, like an unremarkable knoll in a stretch of undulating pasture at Ballynagaul is, on closer inspection, a rath, a type of ringfort formed from earthen banks and ditches that served as enclosed farmsteads during the early medieval period in Ireland, roughly between the fifth and twelfth centuries. Thousands of these enclosures once dotted the Irish countryside, and this one sits quietly among the fields, its circular form still largely legible despite the centuries.

The enclosure is roughly circular, measuring 23 metres north to south and 24 metres east to west. It is not a uniform structure: the northwestern to southeastern arc is defined by an earthen bank that rises 0.45 metres on the interior and 1.1 metres on the exterior, while the opposing arc, running southeast to northwest, takes the form of a scarped edge, meaning the hillside itself has been deliberately cut away to create a near-vertical drop of 2.7 metres across a width of about 6 metres. This combination of built bank and natural scarp, shaped and reinforced by whoever constructed the site, gave the enclosure a clear boundary on all sides without requiring the same effort all the way round. At the eastern edge, a later field boundary has cut into and truncated the bank, a reminder of how subsequent agricultural activity has gradually reshaped these sites over generations. The interior, grassed over, slopes gently downward toward the south. The record was compiled by Denis Power and uploaded in August 2011.

The site sits in working farmland, so access would depend on the cooperation of whoever holds the surrounding fields. The earthwork is most readable in low winter light or early morning, when raking shadows pick out the difference in ground level between the scarped southern face and the flatter interior above. The grassed-over interior offers little to see at surface level, but the contrast between the modest interior bank height and the considerable drop of the scarped edge is more striking in person than measurements alone might suggest.