This one in Mitchelstowndown East, County Limerick, announces itself with almost nothing at all. It exists, in practical terms, as a circular shadow glimpsed from above, a cropmark visible for a moment in a 1984 aerial photograph and since swallowed back into the landscape without leaving so much as a ripple on the surface.

The site came to light during aerial survey work carried out in connection with the Bórd Gáis Éireann Curraleigh West to Limerick gas pipeline. Photographs taken on the 3rd of November 1984, catalogued under reference BGE 1/5000, frame 2779, Site 244, showed a circular cropmark in wet pasture in the south-western quadrant of a broader cluster of monuments, recorded in the Sites and Monuments Register as LI049-027001 to 009. A cropmark forms when buried features, such as the filled-in ditch of an old enclosure, affect how vegetation grows above them, creating patterns only legible from altitude. It is a fleeting kind of evidence, dependent on the right season, the right crop, and the right angle of light. The feature was not marked on the Ordnance Survey Ireland six-inch maps, suggesting it had not registered as anything notable to earlier surveyors working at ground level. When Digital Globe ortho-imagery was taken between 2011 and 2013, and when Google Earth images were subsequently examined, no surface trace could be detected. The record was compiled by Fiona Rooney and uploaded to the national monuments database in September 2021.

There is, honestly, very little to see on the ground. The site sits in wet pasture, and without specialised equipment or access to the original aerial photographs, a visitor would have no way of locating it with any confidence. What makes it worth knowing about is less the place itself than what it represents: the category of site that exists only as data, recorded once under particular atmospheric conditions and then effectively invisible again. The surrounding monument group gives the area genuine archaeological density, and anyone with an interest in the wider landscape of early settlement in County Limerick might find the cluster worth tracing on a map, even if this particular feature within it remains stubbornly out of reach.