What survives is enough to read the original shape: an oval enclosure measuring roughly 44 metres from west-southwest to east-northeast and 37 metres across the shorter axis. A later field wall has cut straight through the monument at two points, the kind of agricultural intrusion that quietly dismantles ancient boundaries over generations without any single dramatic moment of destruction.

A rath, as this type of monument is classified, was the most common form of enclosed settlement in Early Medieval Ireland, typically dating from around the sixth to the twelfth century. These were usually farmsteads, their earthen banks defining a domestic space rather than a defensive one in any military sense. The bank at Ballybrone once ran continuously from the west-southwest around through the north to the east-northeast, though it is now substantially denuded. Where the field wall crosses and the original earthwork has been lost, a degraded scarp, essentially a worn slope in the ground, takes over as the enclosing element to the southeast. Ten metres to the west-northwest, a stone structure of uncertain type sits in close proximity, its relationship to the rath unresolved.