The larger of two circular enclosures here measures roughly fifty metres across and is just about readable on the ground as a shallow, dished depression in the grass, edged by a low bank no more than sixty centimetres high and up to ten metres wide. A second, smaller enclosure, around thirty metres in diameter, attaches to the western side of the larger one, but it leaves no impression whatsoever at ground level. It is only from the air that the full plan becomes legible, the outlines of both enclosures emerging as cropmarks, the kind of differential growth in vegetation that reveals buried features when photographed from above under the right conditions.

The site is almost certainly a rath, the Irish term for a ringfort, which was the dominant form of enclosed rural settlement in early medieval Ireland, broadly from the sixth to the twelfth century. A rath typically consisted of a circular earthen bank and an external ditch, known as a fosse, enclosing a farmstead. They were built by families of middling status and served as both residence and enclosure for livestock. The example at Grange follows that pattern, with a single fosse defining the main enclosure. What makes it slightly less typical is the smaller enclosure appended to the west, a feature sometimes interpreted as a secondary stock enclosure or annexe. Aerial photographs also reveal three or four pits within the interior of the larger enclosure, though their purpose is unclear without excavation. A second enclosure site lies approximately fifty-five metres to the north-west, suggesting this part of County Wexford was more densely settled in the early medieval period than the quiet field on a south-facing slope might now suggest.