In a field in Kilmurry, Co. Kildare, there is something that cannot be seen from the ground at all. A circular enclosure roughly twelve metres across lies buried beneath the soil, invisible to anyone walking past, yet legible from above as a faint discolouration in a crop. These cropmarks form when buried features, ditches, walls, or mounds, affect how plants grow over them. Soil above a filled-in ditch retains more moisture and nutrients, so the crop above it grows fractionally taller or greener, and from altitude the outline of something long gone suddenly reappears.

The enclosure at Kilmurry came to light through aerial imagery captured on 28 June 2018 and was subsequently compiled by Caimin O'Brien, drawing on details provided by Edward O'Riordan. At approximately twelve metres in diameter, the circular form is consistent with a range of early features found across the Irish midlands, from ring-barrows, which are low funerary mounds enclosed by a surrounding ditch, to small enclosures associated with early settlement. Without excavation, the precise function and date of this particular feature remain unknown. What is certain is that the ground here holds a structure of some kind, one that left its mark on the earth deeply enough to be still traceable more than a thousand years, or perhaps several thousand years, after it was made.