It measures only five metres across, its boundary marked by a low earthen scarp and a shallow fosse, the fosse being a type of ditch commonly associated with prehistoric burial monuments, cut into the earth to define and enclose a sacred interior. What survives is modest in scale but coherent in form: a level, unencumbered interior, and the remnants of an outer bank that can still be traced along the north-west to north-east arc and again from the south-east to south-west, though it has disappeared at ground level elsewhere around the circuit.

The monument belongs to a category known as a ring barrow, a form of funerary earthwork found across Ireland and Britain and generally associated with the Bronze Age, though some examples date to the Iron Age. Ring barrows typically consist of a low central mound or flat area enclosed by a ditch and an outer bank, and were used for burial, possibly for individuals of some local standing. This particular example was not identified in its own right but came to attention during a field inspection of a neighbouring ditch-barrow located just eight metres to the north-west. That proximity is itself notable. The clustering of burial monuments in the same small area of ground suggests this part of Ballynagrana held some significance over a long period, with the two monuments placed in close relation to one another across the slope.