The example at Shankill in County Kilkenny does the opposite. It occupies a valley floor, in wet marshy pasture, which already makes it worth a second look. What complicates the picture further is its water management. The fosse, a defensive ditch that typically rings such enclosures, is dry on its south-western side, but elsewhere it is fed by a spring that rises in the north-west and flows around much of the perimeter in a continuous loop, running north, east, and south before turning back westward. Whoever built this structure appears to have channelled a natural water source to fill the ditch deliberately, creating something closer to a moat than a simple earthwork.

The enclosure itself is substantial: an oval roughly 32 metres on its north-east to south-west axis and 41 metres across the other way. The earthen bank is flat-topped, standing about one metre above the interior floor and two metres above the outer ground level, with an overall width of around four metres. The fosse is three metres wide and approximately one metre deep. A three-metre entrance gap in the north-east sector is crossed by a steep ramp over the ditch. The interior is level. That combination of a valley-floor setting, a spring-fed moat, and a formal ramped entrance prompted the surveyor who examined the site to raise a quiet but significant question: whether this is, in fact, a ringfort at all. The deliberate exploitation of a natural spring to achieve what amounts to wet-moat defence is not a feature typically associated with the rath tradition, and points toward a different function or a later date than the early medieval period usually assigned to such earthworks.