A ringfort, or rath, was a roughly circular earthen enclosure used in early medieval Ireland as a farmstead, its banks and ditches defining a domestic territory rather than a military one. The example at Ballyhally was complete enough to be marked clearly as "Fort" on the Ordnance Survey edition of 1836, a full circular enclosure recorded and named at a moment when such features were still being catalogued across the Irish countryside.

Sometime between that survey and the present, the enclosure was largely lost. Modern farm buildings now occupy most of the site, and what survives is a single steep scarp, an abrupt slope in the ground that traces an arc from north-northeast around through east to south. It is the ghost of a perimeter. The drumlin setting is worth noting: drumlins are the smooth, elongated hills left across counties like Cavan by retreating glaciers, and early settlement frequently favoured their summits for the combination of visibility and natural drainage they offered. The rath at Ballyhally would once have commanded a clear view across that characteristic rumpled landscape.