It measures roughly 120 metres across, defined by a low earthen bank and a shallow external fosse, that is, a ditch running around the outside of the bank. The combination of those two features, bank and fosse, is the kind of thing that tends to attract archaeological attention, since similar arrangements turn up at prehistoric enclosures, ringforts, and other early earthworks across Ireland.

What makes this particular enclosure quietly puzzling is the label. A nursery, in the eighteenth and nineteenth century landscape tradition, referred to a managed planting ground, a dedicated area within a demesne where young trees or shrubs were propagated before being transplanted elsewhere in the designed landscape. The internal paths shown on the 1838 map are consistent with that use, suggesting a working horticultural space laid out with some geometric intention. The current assessment is that the earthwork is probably a landscape feature, connected to the ornamental or productive management of the Kippure House demesne rather than to any prehistoric or early medieval activity. But the sheer scale of it, a circle of 120 metres in diameter, is striking for what would otherwise be a functional garden enclosure, and the possibility that an earlier earthwork was adapted or incorporated into the later designed landscape has not been entirely dismissed.