At Ardra in County Cork, a circular enclosure roughly forty metres in diameter appears on the 1842 Ordnance Survey six-inch map as a dotted outline, the cartographers' way of indicating something uncertain or partially visible even then. Today, there is no surface trace whatsoever. The field it once occupied is under tillage, the plough having done, over generations, what time alone might have taken centuries longer to accomplish.

The enclosure sat on a north-facing slope, approximately fifty metres to the east of a separate circular enclosure nearby, suggesting this was not an isolated feature but part of a wider pattern of early settlement or land use in the area. Circular enclosures of this kind are generally associated with early medieval Ireland, the most familiar form being the ringfort, a farmstead enclosed by an earthen bank and ditch. Whether this example at Ardra was a ringfort, a ceremonial enclosure, or something else entirely is impossible to say now. What the 1842 map preserves is a moment when the feature was still legible enough to record, if only tentatively, before it vanished entirely beneath successive seasons of agricultural work.