Walk across the pasture today and nothing obvious announces itself; no earthwork breaks the surface, no bank or ditch interrupts the grass. Yet the Ordnance Survey's six-inch map of 1839 recorded something here clearly enough, a circular embanked enclosure roughly 45 metres in external diameter, sitting on a south-west-facing slope at the head of a small valley running north-east to south-west.

Embanked enclosures of this kind are found across Ireland, and their purposes vary considerably. Some were ringforts, the enclosed farmsteads of early medieval landholders, defined by one or more earthen banks and their corresponding ditches. Others served ritual or ceremonial functions, their origins sometimes stretching back further than the early medieval period. Without excavation it is rarely possible to say which category any particular example belongs to, and Ballygullen offers no obvious clues from the surface. What the 1839 map captures is a monument that was apparently still legible to the surveyors who walked this landscape nearly two centuries ago, though whatever relief it once had has since been levelled, most likely by prolonged agricultural use of the land.

The valley setting is worth pausing over. Enclosures placed at the head of small sheltered valleys were often chosen with practical logic in mind, offering some protection from wind and reasonable drainage on a sloping site. The south-westerly aspect would have caught available light across much of the day. The monument at Ballygullen is now invisible at ground level, which makes it an unusual case: a site whose existence depends entirely on the documentary record of a survey carried out when Victoria had just come to the throne, and whose physical form has since been quietly erased by the ordinary business of farming.