On a north-east-facing slope above Ketragh Glen in north Cork, a ringfort once stood that would have been, by any measure, a substantial presence in the early medieval landscape. Roughly fifty metres across and originally defended by two concentric earthen ramparts, it has since been ploughed flat. Stand in the field today and the ground gives nothing away.

A ringfort, or rath, is an enclosed farmstead of the early medieval period, typically defined by one or more circular earthen banks and ditches. They were the dominant form of rural settlement in Ireland for several centuries, and thousands survive in varying states of preservation. This one, on land formerly belonging to a P. Hartnett, was recorded in 1934 by a researcher named Bowman, who measured its diameter at forty-seven yards and noted that while the outer rampart had already been levelled by that point, the inner one still stood around six feet high. By the time Ordnance Survey editions of 1842, 1905, and 1937 had each faithfully depicted it as a hachured circular enclosure on their six-inch maps, the site was already in agricultural use. At some point after the later surveys, the inner rampart followed the outer into the soil. What remains visible now is not on the ground at all but from the air: aerial photography has revealed the ghost of the original bank and its external fosse, a ditch running around the outside of the enclosure, showing up as a cropmark when differing soil moisture causes the vegetation above buried features to grow unevenly. There is also a subtler survival at ground level; the field boundary along the southern edge of the enclosure kinks slightly out of line, a small deviation that may reflect the course of the second bank still influencing the lay of the land beneath.