What gives this modest earthwork its quiet interest is a question that remains unanswered. Somewhere in the interior of this ringfort on a low east-west ridge at Caherbaun, a sunken depression, eight metres long and up to a metre deep, filled with loose cairn material, may be the collapsed roof of a souterrain, an underground passage or chamber typically used in early medieval Ireland for storage or refuge, or it may simply be a quarry pit left behind by whoever built the enclosure in the first place. The ambiguity is unresolved, and the feature sits there still, neither excavated nor explained.

The ringfort itself, known in Irish as a rath, is a circular earthen enclosure of the kind built by farming families across Ireland roughly between the fifth and twelfth centuries. This example measures thirty-five metres in diameter and retains a flat-bottomed fosse, the technical term for the surrounding ditch, that is between five and seven metres wide and up to one and a half metres deep on the interior side. A causeway five metres wide leads to the entrance on the south-east, a detail that suggests some deliberateness in its orientation and approach. The bank that defines the interior is now only about thirty centimetres high in places, low enough that the whole thing reads, from a distance, as little more than a scrub-covered rise in the ground. Roughly fifty metres to the east, a second rath survives, making Caherbaun one of those places where paired or clustered ringforts hint at a more organised early medieval landscape than the solitary monument usually suggests.