In a field of reclaimed pasture in County Limerick, roughly fifty metres west of the Morningstar River, something circular lies buried beneath the grass, invisible to anyone walking past, invisible on satellite imagery, and absent from every historic Ordnance Survey map ever produced. The only evidence that anything is here at all is a faint cropmark, the kind of ghostly outline that appears when buried features cause the vegetation above them to grow slightly differently, betraying the shape of whatever lies beneath.

The cropmark, catalogued as Site No. 040194, was spotted not by an archaeologist on foot but by someone examining aerial photographs taken on 3 November 1984. Those photographs were commissioned by Bórd Gáis Éireann during the survey work for a gas pipeline, at a scale of 1 to 5000. The image reference is BGE 1/5000 2560. The site sits just inside the Adamstown townland boundary, with the Morningstar River marking the edge of the neighbouring townland of Newtown to the east. Beyond its circular shape, nothing definitive is recorded about what the feature actually is. Circular earthworks in Irish contexts can represent anything from ring forts, which were enclosed farmsteads typically dating from the early medieval period, to Bronze Age barrows or later field enclosures, but no excavation or further investigation appears to have taken place here to narrow it down. The record was compiled by Martin Fitzpatrick and uploaded in June 2021.

Because there are no surface remains, a visit to the field itself would reveal little to the naked eye. The cropmark is only discernible from the air and under the right conditions, typically when differential growth in grass or crops is pronounced during dry spells in summer. The Morningstar River, which forms the nearby townland boundary, provides a navigational reference if you are trying to orient yourself in the landscape. The site is on private farmland, and the ground gives nothing away. What remains is essentially a question mark in a pasture, recorded once on a November afternoon four decades ago and not substantially revisited since.