The structure is a rath, the Irish term for a ringfort, the circular or subcircular enclosure of banked earth that was the dominant form of rural settlement in early medieval Ireland, typically dating from roughly the sixth to the twelfth century. This one measures approximately 31 metres north to south and 28 metres east to west, which puts it at an ordinary domestic scale, the kind of enclosure that would once have enclosed a farmstead and its outbuildings.

The rath sits in level grassland and is poorly preserved. A low bank still defines the northeast and southwest arcs, while elsewhere only a scarp, a slight step or slope in the ground, marks where the boundary once ran. A shallow external fosse, the defensive ditch that would originally have run around the outside of the bank, survives along the northern, eastern, and southern sides. The interior has not been untouched by later use; quarrying has disturbed the northeast section, removing material that might otherwise have yielded some stratigraphic evidence of what stood inside. Roughly 100 metres to the northwest, a separate earthwork survives, suggesting that this corner of Bunavan preserves the traces of a small cluster of early activity rather than a single isolated monument.