A roughly circular platform, approximately thirty metres across, rises just enough above the surrounding land to suggest that something deliberate once shaped it. It is the kind of earthwork that rewards a second look, the sort of thing that passes for an unremarkable rise in the terrain until you consider that the ground has been holding its shape for, most likely, more than a thousand years.

Enclosures of this type are among the most common archaeological features in the Irish landscape, though common does not mean well understood. They are generally thought to represent enclosed settlement sites, the raised or embanked boundaries of farmsteads, family compounds, or small defended homesteads dating broadly to the early medieval period. The interior platform, where it survives, often marks accumulated occupation layers, centuries of habitation pressing gently into the earth. At Ahena, the feature was documented by Murphy in 1998, with the raised platform remaining visible on aerial photography, that slightly elevated, circular form legible from the air in a way it might not be to someone standing in the field itself.