The earthwork at Ballynahinch is not marked on any historic Ordnance Survey Ireland maps, which means generations of cartographers passed over it entirely, either unaware of its presence or uncertain what to make of it. Its existence as a recognised monument rests almost entirely on what aircraft and satellites have been able to see from above.

The site was first recorded in an oblique aerial photograph taken on 21 July 1967, part of the Cambridge University Collection of Aerial Photography (reference CUCAP ADT057). What that image captured was the outline of a raised, roughly rectangular area measuring approximately 79 metres along its northwest to southeast axis and around 50 metres across. Later orthoimage surveys, including Digital Globe imagery taken between 2011 and 2013 and subsequent Google Earth imagery, confirmed the shape more precisely. The monument is defined by a scarp, which is essentially a steep face in the ground where the terrain drops away, combined with a fosse, the term used for a ditch or moat-like feature running along the northern, eastern, and southern sides. Along the western edge, a relic watercourse runs northwest to southeast, suggesting that water management or natural drainage once played a role in how this enclosure functioned or was bounded. A separate rectangular enclosure lies around 70 metres to the northwest, hinting that this corner of the Morningstar river catchment may have held more deliberate human arrangement than the current pastoral landscape suggests. The record was compiled by Fiona Rooney and uploaded to the national monuments database in August 2021.

The site sits 35 metres north of a stream that feeds into the Morningstar river, and roughly 290 metres east of Ballynahinch House. Access to the field itself would require landowner permission, as it lies in private agricultural land. The earthwork is not signposted and there is nothing at ground level that immediately announces itself to a casual eye, though the raised area and the slight drama of the scarp edges may be perceptible underfoot in drier months. Wet conditions, common to this type of low-lying pasture, make the site easier to read from above than from within it, which is perhaps why it took an aeroplane in 1967 to formally notice it at all.