This one, on the eastern bank of the Flesk River near Cahernane in County Kerry, exists only as a ghost in a photograph. The northern arc of what appears to be a circular enclosure, roughly ten metres across, showed up as a shadow site in aerial photography taken in 1956, its outline pressed faintly into the pasture below. At the centre of that arc, there is the suggestion of a second circular feature, smaller and harder to read. Walk the same ground today and you would see nothing at all.

Shadow sites of this kind appear when differences in soil depth, moisture, or buried stone cause grass or crops to grow at slightly different rates, producing tonal variations that are invisible to someone standing among them but legible from the air. The 1956 photograph captured conditions just right to reveal what lies beneath the pasture near the Flesk, a river that flows through the Killarney valley before joining the Laune. Whether the enclosure is a ringfort, a field boundary of some earlier agricultural system, or something else entirely remains unclear. A smaller enclosure has been recorded immediately to the south-west, which at least suggests this stretch of riverbank saw sustained use at some point in the past, even if the nature and date of that use cannot yet be pinned down.