This rectangular earthwork, measuring approximately 39 metres north to south and 28 metres east to west, consists of an earthen bank that rises three-quarters of a metre on the inside and half a metre on the outside. The bank encloses the site on three sides; to the north, east, and south; whilst a defensive fosse, or ditch, about 1.3 metres deep runs along the exterior. The western side has been lost to progress, truncated by a deep, wide cutting made during the construction of the railway line sometime after the site was first mapped in 1842.

The 1842 Ordnance Survey six-inch map shows the site as it once was: a complete rectangular enclosure measuring roughly 55 metres east to west and 45 metres north to south, marked with the distinctive hachured lines that Victorian cartographers used to indicate earthworks. Today, the interior of the site is partially overgrown, nature slowly reclaiming what was once a fortified homestead. These moated sites are characteristic of Anglo-Norman settlement in medieval Ireland, typically dating from the 13th to 14th centuries, when colonists needed defendable farmsteads in contested territories.

Such earthworks served multiple purposes beyond defence; the surrounding ditch would have provided drainage in Ireland’s wet climate, whilst the raised platform kept buildings dry and the bank offered shelter from prevailing winds. Though modest compared to stone castles, these moated sites were the backbone of medieval rural settlement, housing minor lords, prosperous farmers, or estate managers who controlled the surrounding agricultural lands. The survival of Ballycoskery’s earthworks, despite the railway’s intrusion, makes it a valuable piece of Cork’s archaeological landscape.