Historical maps from 1839 and 1908 show it as a rectangular enclosure, measuring approximately 45 metres north to south and 60 metres east to west, surrounded by an earthen bank. These moated sites, which were particularly common in the eastern counties of Ireland, served as fortified homesteads for Anglo-Norman settlers and wealthy Irish families from the 13th to 15th centuries.

The site would have originally featured a deep, water-filled moat surrounding a raised platform where a timber hall or stone building once stood. This defensive arrangement provided both security and status for its inhabitants, marking them as landowners of some importance in medieval Carlow. The rectangular shape of the Knockballystine site was fairly typical for these structures in Leinster, though some moated sites elsewhere in Ireland adopted square or irregular plans depending on local topography.

Unfortunately, like many of Ireland’s earthwork monuments, the Knockballystine moated site fell victim to agricultural improvements and land clearance in the 20th century. Archaeological records indicate it was completely removed sometime before 1973, erasing this piece of medieval heritage from the landscape. Today, nothing remains visible of what was once a significant defensive structure, leaving only the historical maps and archaeological surveys to tell its story. This information comes from the Archaeological Inventory of County Carlow, originally published in 1993 by the Stationery Office in Dublin, with updates incorporated from more recent research.