The rath at Drumirril in County Monaghan is one such place, and what makes it quietly striking is not what survives but what has been lost, and how recently. A rath is an earthen ringfort, a roughly circular enclosure defined by one or more raised banks and ditches, built throughout Ireland broadly during the early medieval period as a farmstead and settlement form. This one sits on the south-west-facing slope of a drumlin ridge running north-west to south-east, the kind of gently rolling glacial landform that defines much of Monaghan's landscape.

What the historical record reveals is an absence as much as a presence. Neither the 1834 nor the 1907 editions of the Ordnance Survey six-inch map show any feature here at all, which is unusual. Ringforts were being recorded with reasonable consistency by the mid-nineteenth century, so to be missing from two successive surveys suggests the site was already heavily degraded, or simply overlooked. By 1967, when field investigators caught up with it, a portion of an earthen bank was still visible at the north-west arc of the enclosure, measuring eight metres in width, roughly one metre in height on the interior face, and slightly less on the exterior. The surviving chord of that arc was recorded at twenty-one metres. Sometime between 1967 and 1984, even that remnant was removed, most likely by agricultural clearance. What had persisted for well over a thousand years was gone within a generation.