The main feature is a steep-sided circular mound, roughly 40 metres across and rising 9 metres high; a substantial defensive structure that would have been topped with wooden palisades and buildings during its active use. This motte is surrounded on its northern and eastern sides by a deep, wide fosse (defensive ditch) that drops about 4 metres below the outer bank, with the ditch itself measuring 3 metres wide at its base.

Adjacent to the northwest of the motte lies a rectangular bailey, measuring 24 by 46 metres, which would have served as an enclosed courtyard for everyday activities, storage, and additional defences. This bailey is protected by its own low bank and external fosse, approximately 3 metres wide, creating a secondary line of defence for the complex. Careful observation reveals traces of stone wall foundations both on the summit of the motte and within the bailey area, suggesting more permanent structures once stood here alongside the earthworks.

The site represents a typical example of Norman military architecture in Ireland, likely constructed in the late 12th or early 13th century as the Anglo-Normans consolidated their control over the region. Its strategic position overlooking the river would have allowed the garrison to monitor and control river traffic and the surrounding countryside, while the formidable earthworks provided a secure base for military operations and administration.