In the low-lying pasture of Rathmore South, County Limerick, the boundaries of a farming landscape that predates anything living memory can recall are visible not in stone walls or earthen banks, but in the grass itself, and only from the air, and only at the right time of year. The site covers roughly fourteen hectares, a subrectangular sweep of land cut through by modern drainage channels and watercourses, and what survives of the original layout appears as cropmarks, the faint differential growth in crops or grass that betrays buried features beneath the soil. Some of these linear marks intersect at right angles, suggesting a organised field pattern rather than casual, piecemeal division of land.

The site first came to light through aerial photographs taken for Bord Gáis Éireann and later confirmed by Archaeological Survey of Ireland images captured in September and October of 2002. Those photographs revealed a series of intersecting linear cropmarks clustered around a ringfort, a circular earthwork enclosure of the kind commonly associated with early medieval settlement in Ireland, which sits within the southern half of the field system. The townland boundary with Dunkip runs along the southern edge, and at least one field from the ancient pattern is thought to survive as part of the present-day field system, a quiet continuity across however many centuries separate the two. The monument was subsequently identified on Ordnance Survey Ireland aerial orthoimages taken between 2005 and 2012, and on Digital Globe imagery from 2011 to 2013, though by the time a Google Earth image was captured in June 2018, the cropmarks were no longer legible. The record was compiled by Alison McQueen and Vera Rahilly and uploaded in November 2020.

There is nothing to see at ground level, which is part of what makes this site unusual as a piece of the archaeological record. The pasture is working farmland, cross-hatched with land drains, and the features that define the monument exist essentially as information encoded in the soil, readable only under particular atmospheric and growing conditions from altitude. For those interested in how such sites are studied, the Bord Gáis Éireann aerial photographs and the Archaeological Survey of Ireland images remain the primary evidence. The lesson of the 2018 Google Earth image, which shows nothing, is worth sitting with: the visibility of cropmark sites is seasonal and variable, and absence of evidence in one photograph is not evidence of absence in the ground.