It is not a fort, not a fairy ring in any folkloric sense, and not an ancient monument in the usual understanding. It is, as far as surveyors can determine, a deliberate piece of garden theatre, a circular earthwork built to hold a ring of trees, designed to be looked at rather than entered or defended.

The feature shows up on the 1837 edition of the Ordnance Survey six-inch map as a sub-rectangular area defined by trees, clearly a considered element of the designed landscape around Carrickglass House. By the time of the latest OS edition, it had disappeared from the cartographic record entirely, the trees presumably long gone. What remains on the ground is a roughly oval enclosure, internally about 38 metres across on its longer axis and 29 metres on the shorter, edged by a low earthen bank and a shallow external fosse, the term for a defensive or ornamental ditch, though here any defensive purpose is purely theatrical. The bank rises only about 0.4 metres on its outer face, and the fosse is a modest 0.3 metres deep; these are not the proportions of anything built for protection. No gap or entrance survives in the bank, which suggests the original opening may have been through a planting arrangement rather than a break in the earthwork itself. Tree-rings of this kind were a fashionable ornamental device in eighteenth and early nineteenth-century demesne landscaping in Ireland, used to create focal points in parkland views, shelter grazing animals in style, or simply to impose a sense of geometric order on otherwise undifferentiated ground.

The feature sits on flat grassland within the broader Carrickglass estate, in ground that is notably wet and marshy, which may partly explain why the trees that once defined it did not survive. Visitors walking the demesne today would need to know what they were looking at to recognise it; the earthwork is subtle, and without the trees it was always meant to carry, its original character requires a little imagination to reconstruct.