The barrow at Tankardstown, County Limerick, belongs firmly to the second category. A barrow is a burial mound, typically of prehistoric origin, raised over the remains of the dead and sometimes accompanied by grave goods. This particular example leaves no impression whatsoever on the ground as it appears today, absorbed into reclaimed pasture and absent from the Ordnance Survey's historic mapping entirely.

The site came to light not through excavation or archival research but through a chance encounter with aerial photography. On 3 November 1984, a survey photograph taken at a scale of 1:50,000 for the Bórd Gáis Éireann gas pipeline, reference number BGE 1/50000, 2549, revealed a small circular cropmark in the soil below. Cropmarks form when buried features, walls, ditches, or mounds, affect how vegetation grows above them; in dry conditions especially, a buried structure can leave a ghostly ring or outline legible only from altitude. The circular mark at Tankardstown was tentative enough to be logged as a possible site rather than a confirmed one. It sits in the western quadrant of a broader cluster of barrows in the area, catalogued under the references LI040-048001, 048003, and 048006, suggesting that the landscape here once held considerably more funerary significance than its present pastoral appearance implies. The record was compiled by Fiona Rooney and uploaded to the national monuments database in May 2021.

By the time orthophotography was carried out between 2005 and 2012, and again on more recent Google Earth imagery, no surface trace remained. The reclaimed pasture has done its work thoroughly. For anyone curious enough to visit Tankardstown, there is nothing to see in the conventional sense, no earthwork, no marker, no visible boundary. The interest lies precisely in that absence, and in what the 1984 photograph quietly recorded before the evidence faded further into the soil.