When viewed from above, a curved ditch traces an arc across the soil from south-southwest to north, covering roughly 72.5 metres, its outline betrayed not by any visible earthwork but by the crops growing above it. This is a cropmark, a phenomenon where buried features such as ditches or walls affect how plants grow overhead; a filled-in ditch retains more moisture than the surrounding subsoil, causing the vegetation above it to grow taller or greener, and so the outline of something long vanished becomes briefly, seasonally legible from the air.

The field sits adjacent to what was once a lough to the east, now dried up. That former body of water is worth pausing on. Enclosures built near wetlands and lakes are a recurring feature of early Irish settlement, and the combination of a curved ditch and a former lough edge raises the possibility that this boundary once formed part of a larger landholding or enclosure whose relationship to the water was deliberate rather than incidental. The arc of the ditch suggests something more considered than a simple field division. Whether this dates to the early medieval period or some other era, the notes do not say, and the site has not been excavated or definitively classified.

The cropmark was identified on Apple Maps satellite imagery, which has increasingly become a tool for spotting features invisible at ground level. At Killuragh, the right growing season and the right angle of light are what make the buried ditch legible, which means the feature can disappear entirely depending on the crop, the weather, and the time of year. It is the kind of site that rewards looking twice at something ordinary.