The enclosure shows up as a cropmark, a phenomenon where buried or disturbed soil causes overlying grass or grain to grow differently, betraying the outline of something long vanished beneath the surface. This particular mark is roughly circular, cut across on its eastern side by a field boundary that was drawn at some point after 1700, giving the surviving impression a flattened, D-shaped appearance. What lies beneath has never been excavated, but the shape and scale are consistent with the kind of enclosed settlement features found widely across early medieval Ireland.

The site was not recorded on the historic six-inch Ordnance Survey maps, which means it escaped formal notice during the great nineteenth-century mapping surveys of Ireland. Its existence only came to light through aerial photography commissioned for the Bórd Gáis Éireann Curraleigh to West Limerick gas pipeline, a survey carried out on 3 November 1984 at a scale of 1:5000. It appears in that archive as Site 3/25. Later, orthophotographs taken by Ordnance Survey Ireland between 2005 and 2012 confirmed the cropmark, and it remains clearly legible on Google Earth imagery. The site sits immediately west of a separate, already-recorded earthwork complex, suggesting that this part of Killeen may once have held a more substantial cluster of activity than the present empty fields imply. The record was compiled by Fiona Rooney and uploaded to the national monuments database in November 2021.

Because the enclosure survives only as a cropmark, there is nothing visible at ground level under ordinary conditions. Cropmarks tend to show most clearly from the air during dry summers, when moisture stress makes the contrast between disturbed and undisturbed soil most legible. The site lies in private pasture, so access would require landowner permission. The most practical way to see the feature is through the Google Earth imagery referenced in the monument record, or through the National Monuments Service mapping portal, where the site is logged alongside the adjacent earthwork complex. It is the kind of place that rewards a certain kind of attention, one more likely to be studied on a screen than visited in person, at least until someone puts a spade in the ground.