Beneath the crop, on a gently westward-facing slope, lies what was once a rath, a ringfort, the kind of roughly circular earthwork that early medieval farmers in Ireland built as enclosed farmsteads, typically surrounding a house and outbuildings with a bank and ditch. This one has been levelled entirely, folded back into the agricultural land around it.

The Ordnance Survey six-inch map of 1842 recorded it clearly, shown as a hachured circular enclosure with a diameter of around twenty metres and a planted interior. That map evidence is now among the few solid traces that survive. The enclosure was apparently already being managed as planted ground by the mid-nineteenth century, which may have accelerated its gradual disappearance into the worked landscape. A second circular enclosure sits roughly thirty metres to the northeast, suggesting this corner of Ballyandrew was once a more densely settled or organised place than the open tillage fields now imply.