This one, in the townland of Kilmurry (Archer) in County Limerick, sits in low-lying marshy pasture, which makes it quietly anomalous. The choice of such waterlogged ground was not accidental; in early medieval Ireland, a soggy perimeter could serve as a deterrent in its own right, the surrounding wet ground doing some of the defensive work that height might provide elsewhere.

A rath, as this class of monument is generally called, is a roughly circular enclosure formed by an earthen bank and an outer ditch, used in early medieval Ireland most commonly as a farmstead for a single family or small household. The example at Kilmurry (Archer) measures around 32 metres across on its north to south axis. Its enclosing bank survives to an internal height of about half a metre and an external height of just over a metre, with an outer fosse, the ditch that runs around the outside, reaching nearly three metres wide. The bank has been significantly eroded along its southern and north-north-western arc, leaving those sections barely readable in the landscape. At the east-south-east, a gap of roughly 3.6 metres marks what was likely the original entrance, and traces of a possible causeway crossing the fosse at that point suggest how people and livestock would have moved in and out. The interior is level, now lying under ordinary pasture. The site was recorded by Denis Power and uploaded to the national record in August 2011.

Finding monuments of this kind in agricultural lowlands requires patience, since the earthworks can be subtle and the surrounding terrain gives little topographical drama to orient yourself. The bank is most legible where it has not eroded, roughly along the northern and eastern sides, and the entrance gap at the east-south-east is probably the clearest surviving feature. Visiting in winter or early spring, when vegetation is lower and shadows are longer, tends to make the surviving earthworks easier to read from ground level. The interior offers nothing visually striking, but standing within it and noting how close the marshy ground lies gives a genuine sense of why this particular spot was both chosen and, eventually, abandoned.