At Ballynagappagh in County Kildare, there is a monument that no one has excavated, touched, or even walked around with a measuring tape. It exists, as far as the current record goes, only as a mark in a crop. In the summer of 2018, aerial photography captured a circular discolouration in the earth, roughly ten metres across, the kind of faint ghost that dry spells bring to the surface when buried ditches cause the plants above them to grow differently from the surrounding field. That differential growth, sometimes darker, sometimes paler depending on what lies beneath, is what archaeologists call a cropmark, and it is often the only outward sign that something was once deliberately dug into the ground.

What the cropmark traces is almost certainly a ring-ditch, a circular trench that would originally have enclosed a burial mound, a flat cremation deposit, or some other funerary feature. Ring-ditches of this kind are widespread across Ireland and are generally associated with the Bronze Age, though some date earlier or later. At ten metres in diameter this is a relatively modest example. The imagery was captured on 28 June 2018, and the site was subsequently brought to attention through the work of Seán Sourke, with the record compiled by Caimin O'Brien in early 2019. Beyond that, the archaeology of this particular site remains unexamined, its contents and date entirely unknown.