No earthwork rises from the surface, no obvious depression or ridge gives it away, and yet it registers clearly from the air, betraying itself through a patch of differential crop growth, the kind of subtle discolouration in a cereal field that archaeologists have long learned to read as a sign of something buried or disturbed below the soil.

The site sits on the crest of a north-facing field at Jordanstown, in the old barony of Balrothery West, a stretch of County Dublin that preserves a quiet scatter of early earthworks and medieval remains. When the Ordnance Survey mapped the area in 1837, the six-inch sheet recorded this feature as a "moat", the term commonly used at the time for any prominent artificial mound, without necessarily implying a water-filled ditch. The mound itself is oval in plan, approximately twenty-five metres in diameter, a modest but not insignificant size. By 1975, when Healy examined the site, it was already not visible at ground level, meaning that centuries of tillage had effectively levelled whatever profile it once presented to the eye. The aerial photographs taken since, including imagery available through Bing, confirm that the feature survives as a buried or near-surface anomaly rather than as a standing earthwork.

The field is under tillage, so access is not straightforward, and there is little to see from the road or field margin in any season when crops are low or absent. The most useful time to look, if you have access to aerial imagery rather than the ground itself, is during a dry summer when crop stress reveals subsurface features most clearly. The differential growth visible on aerial photographs is the closest thing the site now has to a public face. For anyone compiling a picture of the low-lying but once-significant monuments of north Dublin, the Jordanstown mound is a useful reminder that not all archaeology announces itself.