In a waterlogged field beside the Morningstar River in County Limerick, there may or may not be an ancient enclosure. The official record says it was spotted, logged, and then effectively lost, leaving behind little more than a notation and a question mark.

The site sits in improved wet pasture within a meandering loop on the southern bank of the Morningstar River, which at this point also serves as the boundary between the townlands of Ballygrennan and Ardykeohane. An enclosure, in the archaeological sense, typically refers to a defined area bounded by an earthen bank, ditch, or wall, and in an Irish context such features are often associated with early medieval settlement or farming activity, though they can span a wide range of periods and functions. This particular example was identified not through fieldwork but through analysis of aerial photography commissioned for the Bórd Gáis Éireann Curraghleigh to West Limerick gas pipeline, a photograph catalogued as BGE No. 60. The problem is that the photograph itself has since gone missing from the SMR paper file. The monument does not appear on Ordnance Survey Ireland historic maps, and repeated scrutiny of more recent aerial imagery, including OSi orthoimages from 2005 to 2012, Digital Globe images from 2011 to 2013, and a Google Earth capture from June 2018, has turned up nothing. The record was compiled by Alison McQueen and Vera Rahilly and uploaded in November 2020, but its core evidence remains absent.

The land here is liable to flood, which may partly explain why features come and go depending on season and soil saturation. The river meanders considerably in this stretch, and the topography of such loops can preserve or obscure earthworks in unpredictable ways. For anyone curious enough to visit, the townland of Ballygrennan lies in the broader lowlands south-west of Limerick city, and the Morningstar River is a quiet, unhurried watercourse. What you would be looking for, should conditions ever be right, is an earthwork whose outline has so far refused to reappear. The monument exists in the official record with the careful qualifier "possible", which may be the most honest word in Irish archaeology.