Historical maps from 1908 show this site as a rectangular enclosure measuring approximately 55 metres north to south and 65 metres east to west. The defensive features included a fosse, or water-filled ditch, along the northern and eastern sides, whilst an earthen embankment protected the western approach.

Today, the site has been largely levelled by centuries of farming activity, though keen observers can still spot some traces along the eastern edge where the old defensive ditches once ran. Aerial photographs from the Geological Survey of Ireland captured clearer evidence of the site's layout before modern ploughing obscured most surface features. These images reveal the characteristic rectangular plan typical of Anglo-Norman moated sites, which were common across the Irish countryside from the 13th to 15th centuries.

Moated sites like this one at Tomnasock served as fortified farmsteads for Anglo-Norman colonists and their descendants, providing both security and status in medieval Ireland. The water-filled ditches offered protection from raids whilst also draining the surrounding land for agriculture. Though this particular site has lost much of its physical presence, it remains an important piece of Carlow's medieval heritage, recorded in the Archaeological Inventory of County Carlow and protected under national monuments legislation.