The enclosure at Knockphelagh, in County Tipperary, does none of that. It exists, as far as anyone on the ground is concerned, not at all. Standing in the rough, undulating pasture where it lies, you would see only ordinary fields on a gentle north-north-east-facing slope. The monument is entirely invisible at ground level, known only because an aerial photograph, catalogued as GSI R.427/8, caught something the eye cannot: a roughly circular mark in the earth, around ten metres in diameter, that betrays some long-ago enclosure beneath the surface.

Enclosures of this kind are among the quieter categories of Irish field archaeology. Circular enclosures, which could have served as farmsteads, stock enclosures, or boundaries with ritual significance, were constructed across Ireland from the prehistoric period well into the early medieval centuries, and many have been reduced by centuries of agriculture to nothing more than soil differences or crop marks that only reveal themselves under the right light and from the right altitude. What makes the Knockphelagh example particularly interesting is its proximity to a ringfort, a type of circular earthwork enclosure typically associated with early medieval farming settlements, located roughly 130 metres to the south-west. Whether the two monuments are related in date or function is not recorded, but their nearness to one another in an otherwise unremarkable stretch of poor pasture suggests a patch of ground that people once found worth marking and using.