What survives is barely legible: a low circular platform, roughly 35 metres across, with a gentle curving scarp along its northern edge and a wide, shallow depression to the west that may once have been a fosse, the defensive ditch that typically ringed enclosed settlements of early medieval Ireland. A modern field bank has since been built along the scarp, folding the ancient boundary into the working landscape so thoroughly that the two are now difficult to separate.

Circular enclosures of this type are found throughout Ireland and are most commonly associated with the ringfort tradition, a form of enclosed farmstead that dominated the rural landscape from roughly the fifth to the twelfth century. They were built by farming families rather than kings or lords, and their earthen banks and ditches were as much a marker of status and territory as a means of keeping livestock safe. At Greenville, so little remains above ground that the enclosure is classed as very poorly preserved, leaving its original character and date largely a matter of inference rather than certainty. Whether the hollow to the west was ever a proper fosse, or simply a natural feature that happened to mirror one, is something the surviving earthwork cannot settle on its own.