The catch is that nobody has been able to find it. When surveyors went looking in 1999, the site defeated them entirely, swallowed by dense overgrowth and simply unlocatable on the ground.

The enclosure's existence rests on cartographic evidence rather than direct observation. The Cassini edition of the Ordnance Survey six-inch map, published in 1916, marks the feature as a roughly circular earthwork at this spot in Gragan, on the southern fringe of the Burren in County Clare. Circular enclosures of this kind are a familiar feature of the Irish landscape, ranging from high-status ringforts, which were enclosed farmsteads used from the early medieval period onward, to earlier prehistoric enclosures whose original purpose is often harder to determine. Without being able to examine this one, it is impossible to say which category it might fall into, or how much of it survives beneath the canopy. The hazel woodland that now covers this part of the Burren is itself a distinctive feature of the region, a remnant scrub that colonised the limestone karst after centuries of changing land use, and it has proved a thorough guardian of whatever lies underneath.