Look closer and the ground begins to tell a different story: a grass-covered bank traces a near-perfect circle roughly 35 metres across, and beyond it lies the depression of an external fosse, the encircling ditch that once gave this place its defensive character. A field wall has been built directly over part of the fosse, obscuring the northern arc, but enough survives to read the original form with reasonable confidence.

This is a rath, the most common type of early medieval settlement enclosure in Ireland. Raths were typically constructed between roughly the fifth and twelfth centuries and served as enclosed farmsteads for single family groups, the bank and fosse providing both a physical barrier and a social signal of status and boundary. The one at Curheen follows the standard pattern, though it preserves one detail that lifts it slightly out of the ordinary. A gap roughly 1.7 metres wide at the east-northeast may be the original entrance, still legible after more than a thousand years. More intriguing is a feature noted during an inspection in 1974: a slight bank of earth and stone, about nine metres long, extending southward from the fosse and curving gently to the west. This was tentatively identified as the possible remains of an annexe, a secondary enclosure sometimes attached to raths and thought to have served agricultural or stock-keeping purposes. It is a modest fragment, but the kind of detail that rewards patient looking.