The 1837 Ordnance Survey Fair Plan shows it clearly: an oval enclosure planted with trees inside a second outer oval, labelled simply as 'fort'. Just a year later, the published six-inch map omitted it as an antiquity altogether, reclassifying it instead as a landscaped tree-ring. That small editorial decision, the difference between a prehistoric monument and a Georgian garden feature, sits at the heart of what makes this site genuinely ambiguous.

What survives on the ground is a sub-circular area roughly 24 metres across from north-west to south-east and 26 metres north-east to south-west, enclosed by two earthen banks with a fosse, a ditch, between them and a further fosse on the outside. A ringfort, sometimes called a rath, is an enclosed farmstead of early medieval date, typically circular and defined by one or more earthen banks and ditches; this one fits that description reasonably well. The interior slopes from north-west to south-east, and tree stumps are still visible around the perimeter. The question is whether those trees were always there, the remnant of an ancient enclosure that was later tidied into a garden feature by the owners of South Hill House, or whether the whole thing was constructed as a deliberate landscape ornament with no prehistoric origin at all. The relationship between Ireland's country estates and the ancient earthworks that happened to fall within their boundaries was often complicated; landowners sometimes preserved ringforts as romantic curiosities, sometimes levelled them, and occasionally built new features that mimicked them.