At Windgates in County Kildare, something buried beneath the fields gave itself away on a warm summer's day in 2018, not through excavation or archival research, but through the geometry of grass. A partial cropmark, roughly circular and approximately 27 metres in diameter, appeared in aerial imagery captured on the 28th of June that year. Cropmarks form when buried features, ditches, walls, or pits, affect the growth of crops or grass above them. Soil above a filled-in ditch tends to retain more moisture and nutrients, encouraging lusher, taller growth; soil above a buried wall does the opposite. From the air, these subtle differences in colour and height resolve into shapes that are otherwise invisible at ground level, ghostly outlines of structures that may have vanished from the surface centuries ago.

The circular form is suggestive. Enclosed circular features of this scale are common across Ireland and are frequently associated with ringforts, the farmsteads of early medieval Ireland, typically dating from roughly the fifth to the twelfth centuries. A ringfort of around 27 metres in diameter would be on the modest end of the scale, though not unusually small. Whether that is what lies beneath Windgates is unknown; no excavation record accompanies the observation. The site came to attention through aerial scrutiny of Google Earth imagery, with the detail provided by Jean-Charles Caillère and compiled by Caimin O'Brien in 2019. The cropmark is only partial, which may mean the enclosure is incomplete, that part of it has been obscured or destroyed, or simply that the growing conditions in June 2018 were only favourable enough to reveal a portion of the feature.

What exists here, for now, is a question rather than an answer. A ring in the grass, visible only from altitude and only under particular conditions, waiting for closer investigation.