Some of the most interesting archaeological discoveries in Ireland are made not by excavation, but by looking straight down. In a tillage field at Duneany in County Kildare, a D-shaped enclosure measuring roughly 50 metres north-northeast to south-southwest and 42 metres west-northwest to east-southeast became visible not through any digging, but as a cropmark on aerial imagery captured in June 2018. Cropmarks form when buried features such as ditches or walls affect the growth of crops above them, producing faint but legible shapes that only reveal themselves from altitude, and often only in dry summers when soil moisture differences are most pronounced. The enclosure's distinctive straight edge along its south-eastern side is what sets it apart from the more common circular ringforts of the Irish landscape.

The site sits in a tillage field alongside a second enclosure located approximately 90 metres to the east-southeast, suggesting this corner of Kildare may once have supported more organised settlement or activity than the bare agricultural land now implies. Enclosures of this kind are broadly associated with early medieval occupation in Ireland, though without excavation it is difficult to assign a precise date or function. The pairing of two enclosures in close proximity is a pattern seen elsewhere in the Irish countryside, and sometimes indicates related farmsteads, a principal and secondary enclosure, or activity from different periods reusing the same general ground.