This one is visible only from the air, and only under the right conditions. In a large arable field about 175 metres north-northwest of Baldongan Church in County Dublin, the soil holds the ghost of a curvilinear enclosure, its outline betrayed not by any surface feature but by the differential growth of crops above a buried ditch. These are cropmarks, a phenomenon in which buried features such as ditches or pits retain more moisture than the surrounding subsoil, causing the plants directly above them to grow taller or greener and so trace the hidden form below. The effect is seasonal and fleeting, and it rewards those who know to look for it on aerial photography or satellite imagery.

The enclosure was identified through positive cropmarks captured in Google Earth imagery dated 24 June 2018 and recorded by Tom Condit, whose notes were compiled and uploaded in October 2020. The outline is curvilinear, meaning it follows a roughly circular or oval path rather than a rectilinear one, and it is legible on the north, south, and west sides, though it appears incomplete. Its external dimensions run to approximately 33.7 metres north to south, and the ditch that defines it is around 1.5 metres wide. Close to the south-western corner of the enclosure, there is a possible secondary circular feature, though its nature remains uncertain. Curvilinear enclosures of this type are broadly associated with early medieval settlement in Ireland, where a circular or oval ditch and bank arrangement, known as a ringfort or rath, typically demarcated a farmstead and its immediate surroundings. Whether this example belongs to that tradition or to an earlier period is not yet known.

The site itself is not accessible as a visitor destination in any formal sense. The cropmarks lie beneath a working arable field, invisible at ground level and unaccompanied by any marker or signage. The nearby Baldongan Church, a roofless medieval ruin, is the more tangible point of reference in this landscape and gives a rough bearing for locating the field in question. For those interested in the enclosure specifically, the Google Earth imagery from June 2018 remains the clearest way to observe it, the summer date being significant given that cropmarks tend to appear most strongly during dry spells when moisture differences in the subsoil become most pronounced. It is the kind of site that rewards looking rather than visiting, a reminder that the Irish countryside holds a great deal that is easier to read from altitude than from the road.