The ringfort at Seskin is a rath, the most common type of early medieval enclosure in Ireland, typically constructed between roughly the fifth and twelfth centuries as a farmstead defended by earthworks rather than stone. What makes this one worth a second look is a small detail buried in its profile: at some point in the modern era, somebody dug a shallow trench around the inside perimeter and piled the spoil onto the bank, raising it artificially. The original structure and a later, practical intervention have merged into a single landform.

The enclosure is roughly circular, measuring about 34 metres east to west and 38 metres north to south. Its earthen bank stands around a metre high on the interior side and slightly more on the exterior, where an outer ditch, known as a fosse, runs around it. The fosse here is modest, around three metres wide and only 20 to 30 centimetres deep, suggesting either that it was never especially substantial or that it has silted and settled considerably over the centuries. The interior is flat and tilts very slightly westward toward the stream valley below. The southern edge of the bank has been partly cut away where a farm road was widened, a small but irreversible loss that is common to many such sites across the Irish countryside, where agricultural necessity and ancient earthworks have long shared uneasy ground.