Others exist only as a faint curve pressed into grass, visible not to the eye on the ground but to a camera looking straight down from altitude. The possible earthwork at Duntryleague in County Limerick belongs firmly to the second category, a site so subtly expressed in the landscape that it never made it onto the Ordnance Survey Ireland six-inch maps, the nineteenth-century series that documented the Irish countryside in extraordinary detail. It sits in reclaimed wet pasture, roughly seventy metres northeast of the townland boundary with Killeen, and for most of its existence it seems to have gone entirely unrecorded.

The site first came to notice through an unlikely source: aerial photographs taken on 3 November 1984 during a survey carried out for the Bórd Gáis Éireann Curraleigh West to Limerick gas pipeline. That survey produced a series of strip maps covering the pipeline corridor, and within Strip Map 3, logged as Site 3/39, analysts identified what appeared to be a possible enclosure. Enclosures of this curvilinear type, where a roughly circular or oval boundary is traced in earthwork or ditch, are found widely across Ireland and can date to any number of periods, from the early medieval to far earlier, though nothing in the current record pins this particular example to a specific era. Decades later, the same curvilinear cropmark, the kind of mark that appears when buried features affect how grass or crops grow above them, became visible again in Digital Globe orthoimagery taken between 2011 and 2013, and in subsequent Google Earth images, suggesting the feature identified in 1984 and the mark visible in later satellite photography are one and the same.

Because the site is not marked on any standard mapping and lies within private farmland, there is no conventional way to visit it. The most accessible version of this earthwork is, in a sense, a digital one: the Google Earth orthoimagery that allowed researchers to reconfirm its existence. Cropmarks of this kind tend to show most clearly in dry summers, when moisture stress brings out differences between disturbed and undisturbed subsoil in the colour and height of vegetation above. The record was compiled by Fiona Rooney and uploaded to the sites database in September 2021, a reminder that Irish archaeology continues to accumulate new entries not only through excavation but through the patient re-examination of images that have been sitting in archives, or quietly updating on satellite platforms, for years.