The field in question, reclaimed pasture lying roughly 220 metres north of the Ballinstona North townland boundary and about 290 metres south of Greenpark House, shows no earthworks, no stones, no visible trace of anything at all. And yet, under certain conditions of light and growth, the ground tells a different story.

The site, catalogued as Site No. 039129, was first identified not by excavation or field survey but through the examination of aerial photographs taken on 16 April 1974 as part of the Geological Survey Ireland Aerial Photographic collection (GSIAP, 496). On those images, a circular cropmark becomes legible, the kind of mark that appears when buried features, walls, ditches, or compacted soil, affect the growth of crops or grass above them, making the outline of an ancient enclosure briefly visible from altitude. Circular enclosures of this type are among the most common archaeological features in the Irish landscape, ranging from prehistoric farmsteads to early medieval ringforts, though without excavation it is impossible to say which category this site might belong to. What is notable here is that the site does not appear on Ordnance Survey Ireland historic maps at all, suggesting it was already so thoroughly buried by the time mapping began that it left no impression on the surface record. By the time orthophotography was carried out between 2005 and 2012, there was nothing visible. The cropmark reappeared, however, on a Google Earth image dated 16 March 2016, alongside linear cropmarks that may represent the remains of old drainage channels cutting across the same ground.

For anyone curious enough to seek it out, the location can be narrowed down using the coordinates associated with the site record, positioned in open pasture between the Ballinstona North boundary and Greenpark House. There is nothing to observe from ground level, and access would require permission from the landowner. The real engagement with a site like this is remote, through the aerial photographs themselves, particularly the 1974 GSIAP image in which the circular form is legible. Spring and early summer, when differential crop growth is at its most pronounced, are the periods when cropmarks of this kind are most likely to show up, which may explain why the 1974 photograph, taken in mid-April, captured it at all.