It shows no obvious earthwork, no standing stone, no weathered wall. What reveals it is lidar, a remote-sensing technology that fires pulses of laser light at the ground and maps the returning signals to produce elevation models of extraordinary precision. Under that kind of scrutiny, subtle rises and hollows that centuries of ploughing and vegetation have all but erased can suddenly resolve into geometry, and at Nutgrove the geometry is a near-perfect circle.

Circular enclosures of this kind are among the most common archaeological features found across Ireland, though their dates and functions vary considerably. Some are ringforts, the farmsteads of early medieval families who enclosed their homes and livestock within an earthen bank and ditch. Others are earlier, associated with the Bronze Age or Iron Age, and a small number appear to have had ceremonial rather than domestic purposes. Without excavation or additional survey, it is not possible to say which category this particular example belongs to. What the lidar does confirm is that something was deliberately laid out here, at a scale consistent with human habitation or enclosure, and that the landscape around Nutgrove holds more beneath its surface than is immediately apparent.