Where the fence runs from the south-west around to the north-west, it follows what was once a deliberate boundary; a low earthen arc continues the circuit to the north-north-east and south-east, completing the ring where the modern fenceline leaves off. The overall shape, though worn and partially co-opted, is still legible from the right angle.

Ringforts, known in Irish as raths when defined primarily by an earthen bank and ditch, were the most common form of rural settlement in early medieval Ireland, typically dating from roughly the sixth to the tenth century. They served as enclosed farmsteads, protecting a household and its livestock. What makes the Annagh Beg example quietly notable is the presence of a souterrain in its north-west quadrant. A souterrain is an underground stone-lined passage or chamber, often associated with ringforts, and thought to have served for storage, refuge, or both. The combination of a rath with an attached souterrain is well documented across Munster, but the survival of both features, however reduced, within a working pasture on a north-facing slope gives this particular site a certain understated persistence.