This rectangular earthwork, measuring roughly 60 by 40 metres, consists of a raised platform surrounded by a water-filled ditch; a defensive arrangement that was both practical and symbolic of the landholder’s status. Such sites became common across Leinster and east Munster from the 13th century onwards, as colonists established fortified farmsteads in newly acquired territories.

The moat itself, typically three to four metres wide and up to two metres deep, would have been fed by local streams or springs, creating a formidable barrier against raiders whilst also serving as a source of fish and waterfowl. The raised interior platform likely supported a timber hall house, outbuildings, and perhaps a small chapel, though any above-ground structures have long since vanished. Archaeological evidence from similar sites suggests these homesteads functioned as agricultural centres, managing the surrounding lands and collecting rents from Irish tenants who worked the fields beyond the moat.

What makes Rossaneny particularly interesting is its position within the broader network of Anglo-Norman settlement in south Leinster. Unlike the great stone castles that dominate the historical imagination, these moated sites represent the everyday reality of medieval colonisation; modest fortifications built by lesser nobles and prosperous farmers who sought security without the expense of stone fortifications. Today, the site appears as little more than a tree-lined earthwork in a quiet field, yet it stands as tangible evidence of the profound cultural and agricultural changes that swept across medieval Ireland.