Somewhere beneath the tilled fields of Rathbride in County Kildare, a square enclosure lies invisible at ground level, betrayed only by the crops growing above it. On aerial imagery captured in June 2018, the outline emerges as a cropmark, the kind of ghostly trace that appears when soil disturbed by an ancient ditch retains moisture differently from the surrounding ground, causing the vegetation above it to grow at a subtly different rate or colour. What shows up is a nearly perfect square, roughly 52 metres on each side, its perimeter defined by the cropmark of a fosse, a ditch, running some two to three metres wide.

The enclosure has a possible entrance gap of approximately three metres, positioned almost midway along its eastern side, which is a fairly common placement for such features in Irish prehistoric and early medieval contexts. A later field boundary runs north to south immediately to the west of the site, suggesting the landscape was reorganised at some point after the enclosure fell out of use, without anyone necessarily knowing what lay beneath. The site was identified from the aerial imagery by Jean-Charles Caillère and compiled into the record by Gearóid Conroy. Beyond what the cropmark itself reveals, nothing more is currently known about the enclosure's date, function, or the people who built it.