And yet the absence itself is telling. This was once a ringfort, the kind of roughly circular earthwork enclosure, typically defined by a raised bank and an outer ditch known as a fosse, that thousands of early medieval farming families across Ireland built and lived within. This particular one measured somewhere between 25 and 31 metres across. It sat near the south-western edge of its townland, in softly rolling pasture with patches of wet ground, and it had accumulated at least a thousand years of presence before someone decided, in the 1970s, to level it during land reclamation.

Before it disappeared, it left a paper trail. The earliest surviving name for the site is Lisaniska, which appears on an estate map drawn up in 1811 for Sir Robert Lynch-Blosse, a document now held in the National Library of Ireland. The "Lis" element of that name is itself an indicator of antiquity, being an Irish word for a ringfort enclosure, closely related to the more familiar "rath". The site also appears on Ordnance Survey six-inch maps from 1838 and 1916, marked each time as a roughly circular enclosure, which means that for well over a century it was visible and mappable, a recognisable feature in the landscape. A second rath survives approximately 260 metres to the south-east, which suggests this part of Mayo once supported a modest cluster of such settlements, each perhaps associated with a separate farming household in the early medieval period.

For anyone who knows what to look for, the outline of the levelled enclosure can still be read in the ground: a low, almost imperceptible undulation marking the course of the old bank, and just outside it a faint linear depression indicating where the fosse once ran. The field fence running on a north-west to south-east axis clips the north-eastern edge, bisecting what the bank once described. It is the kind of place that rewards patience and low, raking light, the sort of conditions under which earthworks that have been pressed nearly flat will briefly reassert themselves.