Drumlins, the low elongated hills shaped by glacial activity and characteristic of this part of Ulster, were frequently chosen as the sites of early enclosures precisely because their summits offered natural elevation without requiring major earthwork. The enclosure at Doosky was modest by any measure, but its hilltop placement gave it a presence that belied its size.

The 1834 edition of the Ordnance Survey six-inch map records a circular feature roughly twenty metres in diameter at this summit, marked in gothic lettering as a "fort", the conventional cartographic notation used by the early OS surveyors to indicate an earthwork of presumed antiquity. Gothic lettering was the surveyors' way of flagging what they understood to be ancient or historic features, as distinct from contemporary buildings or field boundaries. By the time the 1907 edition was produced, the feature had either shrunk in appearance or had already suffered some disturbance, appearing then as a much smaller enclosure of around ten metres across. A physical survey carried out in 1968 found that some structural fabric still remained: a curving field bank, about two metres wide and standing to a height of just over a metre on its outer face, ran in a SSE to NW arc across the summit, accompanied by a shallow outer fosse, a type of ditch or drain that typically defined the perimeter of such enclosures. That fragment, roughly eight metres in chord, was the last trace of the original circuit. By 1995, even that had been removed, lost to agricultural clearance or land improvement works of the kind that have erased countless similar features across the Irish countryside during the second half of the twentieth century. The site at Doosky now exists more fully in the cartographic and survey record than it does in the ground.