The ringfort at Coolmona in County Cork was levelled around 1972 during field clearance, leaving the pasture above the Shournagh River valley entirely unmarked. No earthwork, no hollow, no crop shadow in a dry summer. Whatever had survived as a physical presence for more than a thousand years was gone within a single agricultural operation.

Before that happened, the site was well documented. A ringfort, sometimes called a rath, is a roughly circular enclosure defined by one or more earthen banks and an external ditch, most commonly associated with early medieval farmsteads in Ireland. When P. J. Hartnett recorded this one in 1939, he found a single rampart still standing six feet high and 105 feet in diameter, with traces of a fosse, the surrounding ditch, and a clear entrance to the west. The same enclosure had appeared on Ordnance Survey six-inch maps in 1842, 1904, and 1939, depicted each time as a hachured circle of roughly 30 metres across. What makes this particular loss more pointed is the context: this ringfort was one of five, evenly spaced over a distance of 800 metres along the south-facing slope of the Shournagh River valley. The others in the cluster remain on record, and together they suggest a deliberate pattern of early medieval settlement across the hillside, each enclosure positioned within sight or reasonable distance of its neighbours. Coolmona's fort, somewhere in the middle of that arrangement, is now a gap in the sequence.