In the grounds of Palmerstown Demesne in County Kildare, a circle roughly thirteen metres across lies invisible to anyone walking the land above it. It only becomes legible from the air, and even then only under the right conditions: a dry summer, when variations in soil moisture cause the grass or crops growing over a buried feature to ripen or wither at a slightly different rate from the surrounding vegetation, producing a faint but telling discolouration. This is what archaeologists call a cropmark, and it is one of the quieter ways the past makes itself known.

The feature itself is a ring-ditch, a roughly circular trench cut into the ground in prehistory and long since filled in and forgotten. Ring-ditches of this kind are generally associated with funerary or ritual activity, the filled trench often being all that survives of a burial mound whose earthen core has been ploughed flat over centuries of agriculture. The Palmerstown example, with its approximate diameter of thirteen metres, sits comfortably within the range typical of such monuments. It came to light through aerial imagery captured on 28 June 2018 via Google Earth, identified by Jean-Charles Caillère and subsequently recorded by Caimin O'Brien in 2019. Without that particular summer date, the dry ground conditions, and someone looking at the right image, it might have remained unrecorded indefinitely.