Yet that is precisely what survives at Portobello in County Roscommon, a quietly anomalous earthwork sitting on a low rise and defined more by what it lacks than by what it displays. Most raths, as these early medieval farmstead enclosures are commonly known, would once have combined an earthen bank with an external fosse, the ditch from which the bank material was dug, and a clear break in the perimeter to allow access. Here, neither feature is apparent to the eye.

The site takes a D-shape rather than the more typical circular plan, measuring roughly 22.5 metres east to west and 21.5 metres north to south. Its earthen bank varies between two and just over three metres in width, and while it still carries some height, ranging internally from about a quarter of a metre to three-quarters of a metre, and slightly more on the exterior, it has been worn down on the south-east to south-south-west arc into a plain straight scarp rather than a rounded bank. That reduction in profile on one side is worth noting; it suggests either deliberate levelling at some point or differential erosion over many centuries. What is perhaps most striking is that the site appears only on the 1914 edition of the Ordnance Survey six-inch map, meaning it escaped earlier cartographic attention entirely, an absence that raises quiet questions about how well-understood or well-regarded the feature was in the landscape before that date. The perimeter is now planted with mature deciduous trees, which both mark and partially obscure the surviving earthwork.