For well over a century, the Ordnance Survey maps of this part of County Waterford labelled a particular patch of ground as 'Castle (Site of)', yet what survives on the surface looks nothing like a castle at all. What you actually find in Middlequarter is a gently raised, grass-covered disc of earth, roughly 27 metres across, its interior slightly dished, sitting quietly on a level landscape with no obvious break or gap to suggest how anyone ever entered it.

The feature is defined by a fosse, the term for a defensive ditch cut around an enclosed site, and in this case the fosse is unusually wide, measuring between ten and fifteen metres across the top, though relatively shallow, with an internal depth of around 0.4 metres and an external depth of 0.2 metres. That combination of width and shallowness is what makes the classification awkward. A typical ringfort or rath, the kind of enclosed farmstead built across Ireland during the early medieval period, usually has a narrower, more pronounced ditch. The broad, moat-like fosse here raises the possibility that this is instead a circular moated site, a form of enclosure more commonly associated with the Anglo-Norman period, when a wide water-filled or waterlogged ditch served both practical and symbolic purposes around a manorial dwelling or small fortification. The earlier maps presumably picked up a local tradition linking the spot to a castle, and it is easy to see how a site of this kind, with its suggestion of a moat, could carry that memory forward across generations, even as the original structure disappeared entirely from view.