To a casual eye, the earthwork might appear to have two enclosing banks, the hallmark of a bivallate rath, yet the outer ring is not an original defensive feature at all. A later fieldbank, curving neatly around the site as if following an older memory in the ground, has given a single-banked enclosure the appearance of something more elaborate than it actually is.

Ringforts, known in Irish as raths when built from earth, were the most common form of enclosed settlement in early medieval Ireland, typically serving as farmsteads for a family of some status. This example at Coolkeragh is univallate, meaning it was originally defended by a single earthen bank and an exterior fosse, the shallow ditch that runs around the outside of the bank. The enclosing bank itself is well defined: it stands 1.3 metres at its maximum external height and drops to roughly 0.7 metres on the interior face, with a base width averaging around five metres. The whole enclosed area measures 34 metres across internally, a fairly typical scale for a rath of this kind. A gap of about three metres on the eastern side is thought to mark the original entrance, a position that would have allowed an occupant to look out towards the morning light.