It is a rath, the Irish term for a ringfort, the kind of enclosed farmstead that early medieval families built across the Irish landscape in their thousands between roughly the fifth and twelfth centuries. This one sits across a gentle swell in undulating ground, with the land falling away to the east and south-east and dropping slightly to the north, and its dimensions, about 21 metres north to south and 23 metres east to west, place it comfortably within the typical range for a single-family enclosure.

What makes Ballyvicmaha worth attention is the way its builders adapted their work to the natural slope. Where the ground falls away most steeply to the east and south-east, the outer face of the bank rises to between 1.4 and 1.5 metres, compensating for what the terrain takes away. On the western side, where the bank is best preserved, it reaches a width of 3.4 metres and an internal height of 0.85 metres. Elsewhere, a lower stony bank sits atop the earthen scarp, and to the south and south-east this has been reduced to the scarp alone. A gap of about 1.4 metres in the bank at the south-west may mark the original entrance. A heap of stones piled against the external face at the north-east is harder to explain, whether leftover construction material, later clearance, or something else entirely. Later farming activity has left its own marks: a field wall clips the southern scarp, and a north-west to south-east wall that was still visible on the 1922 Ordnance Survey six-inch map, abutting the bank at the north-west, has since been removed.