This ringwork castle at Killamoyne, Rosnamulteeny represents a fascinating example of medieval defensive architecture, though one built from earth and stone rather than the towering masonry we might typically associate with castles.

The structure consists of a circular raised platform, measuring 28 metres across from northeast to southwest, protected by an impressive double ring of defensive banks. Between these two earthen ramparts runs a narrow, deep ditch, roughly a metre wide and a metre deep, which would have presented a formidable obstacle to any would-be attackers. The inner bank remains the most substantial feature of the site, standing 3.5 metres wide and rising to heights of 1.7 metres on the inside and an imposing 3 to 4 metres on the exterior face. The outer bank, whilst more modest at 1.5 metres wide and only 0.2 metres high, still traces the defensive circuit, though a modern road has unfortunately cut through its northern section.

Access to this fortified enclosure was carefully controlled through a single causewayed entrance on the east-southeast side, where a 3.8-metre-wide gap in the banks allowed passage whilst maintaining defensive advantages. This type of bivallate, or double-banked, earthwork represents an important chapter in Ireland’s medieval history, when Anglo-Norman settlers and Irish lords alike constructed these ringwork castles as administrative centres and symbols of power across the landscape.