What remains here is a ringfort, or rath, one of the most common monument types in the Irish landscape, built during the early medieval period, roughly between the fifth and twelfth centuries, as a defended farmstead for a single family or small community. At Forgney, the enclosure is so worn down that it barely registers as anything more than a gentle swelling in the field, its defining bank reduced to a thin, stony ridge no more than twenty centimetres high in places.

The ringfort survives as a raised oval area measuring approximately 27.5 metres east to west and 18 metres north to south. Its enclosing bank of earth and stone, between 2.2 and 2.4 metres wide, has been heavily denuded over the centuries, and there is no surviving trace of a fosse, the external ditch that typically accompanied such a bank and would have added to the sense of enclosure and defence. A narrow break of about one metre in the bank on the north-western side may represent the original entrance. The site appears on the 1837 edition of the Ordnance Survey six-inch map, where it is marked as a circular enclosure labelled simply "Fort", suggesting it was recognisable as an earthwork feature even then, if only barely.