This one near Dromalught, in north Kerry, has done almost the opposite, spending much of the modern era as little more than a shadow in a field. A circular enclosure consistent with an early medieval rath, the kind of earthwork ringfort in which Irish farming families lived and kept their livestock perhaps a thousand or more years ago, it went unrecorded on the Ordnance Survey map of 1841 to 1842, suggesting it had already faded so completely into the landscape that nineteenth-century surveyors either missed it or found nothing worth marking.

It resurfaced, in a manner of speaking, on a later OS edition of 1939, appearing just north of Dromalught Cottage. Then, in 1977, aerial photography carried out by the Geological Survey of Ireland caught it again, this time as a crop mark, the faint but telling discolouration in growing vegetation that betrays buried or semi-buried features beneath the soil. Crop marks of this kind are one of the more quietly remarkable tools in landscape archaeology; differences in soil depth and moisture, caused by old ditches or banks, produce subtly different growth rates in crops above them, and from the air these differences resolve into shapes that are invisible at ground level. The ringfort at Dromalught made itself known in exactly this way. No permission was granted to inspect the site on the ground, so the aerial image remains the primary evidence for what lies there.