Others have almost entirely ceased to exist, surviving only as a faint signature caught by a camera mounted in an aircraft, visible for a moment under the right light and then gone again. The enclosure recorded at Grillagh, in County Limerick, belongs firmly to the second category. It has no presence on the ground that any walker or farmer would recognise, and no cartographic history to fall back on; it does not appear on any Ordnance Survey Ireland historic maps. What it does have is a single aerial photograph, reference GSIAP R448, which was enough for archaeologists to classify it as a potential site.

The record was compiled by Alison McQueen and Vera Rahilly and uploaded in November 2020. The site sits in pasture, roughly 150 metres south-south-west of the townland boundary with Ballynagallagh, a detail that places it in the kind of liminal agricultural ground where enclosures, which are simply defined areas bounded by a bank, ditch, or wall and used variously for settlement, livestock, or ritual purposes across prehistoric and early medieval Ireland, sometimes managed to survive beneath undisturbed grass for centuries. This one, however, did not survive in any meaningful sense. Systematic checks against Ordnance Survey Ireland orthoimages captured between 2005 and 2012, Digital Globe imagery from 2011 to 2013, and a Google Earth image taken in March 2018 all returned the same result: nothing visible. The monument, whatever its original form, has been levelled.

For anyone curious enough to look, Grillagh is a quiet townland in County Limerick, and the boundary with Ballynagallagh is the kind of detail you can trace on a modern mapping application without too much difficulty. The pasture itself is private agricultural land, so access is not a given. What is publicly available, and genuinely worth examining, is the aerial photograph on which the identification rests. Cropmarks and soilmarks, the faint discolourations in vegetation or earth that betray buried features to a camera above, can be extraordinarily subtle, and the fact that this one disappeared entirely from later imagery is a reminder of how precarious the archaeological record can be. Ploughing, drainage, and decades of grazing pressure can erase what took centuries to accumulate. The site at Grillagh is, in a sense, the record of an absence, documented precisely because someone thought to look.