At Cultiafadda in County Galway, a ringfort, the kind of roughly circular earthwork enclosure built in early medieval Ireland to protect a farmstead and its inhabitants, survives nowhere above ground. What was once a semicircular depression of around 35 metres, sitting on the south-western side of a laneway amid bogland and glacial ridges, has been completely erased. A landowner levelled a small sand hill on the site, and only later was told, presumably with some dismay on all sides, that the feature was in fact a fort.

The 1930 edition of the Ordnance Survey six-inch map had recorded the depression faithfully, which is how archaeologists were able to identify what had been lost. The bog and ridge landscape around Cultiafadda is itself a legacy of the last glaciation, the ridges being eskers or drumlins shaped by ice sheets retreating thousands of years ago. Ringforts were typically built during the early medieval period, roughly the fifth to twelfth centuries, and many thousands once dotted the Irish countryside. The Galway boglands preserved a surprising number of them, at least in part, because the ground was difficult to cultivate and develop. This particular one was not so fortunate.