This one was lost to something more deliberate. At Devlis in County Mayo, a rectangular earthwork that had already survived centuries in a ruined state was finally erased when the natural ridge it occupied was quarried away in the late twentieth century. There is nothing to see there now, which makes the early account of it all the more worth preserving.

When the antiquarian H. Knox recorded the site in 1911, it was already much degraded. He described a platform-like enclosure that had been cut, or scarped, directly out of the lower eastern end of an esker, the kind of long, winding gravel ridge left behind by glacial meltwater, which provided a dry, elevated position in an otherwise marshy landscape. Three sides of the enclosure were surrounded by that boggy ground, making the esker both building material and natural defence. The rectangular platform measured roughly 37 metres east to west and 17 metres north to south, with scarps on the northern, eastern, and southern sides rising to about 1.8 metres. On the eastern scarp there was a slight trace of a bank still visible along the top. The western side presented what Knox called a great rampart, also carved into the rising slope of the esker rather than built up from scratch. The site sat in a field known locally as Paurkeen Sam, a name that translates roughly from the Irish as Sam's little park or field, though who Sam was, and when that name attached itself to the ground, is not recorded. By the end of the twentieth century the esker itself had been largely quarried away for its gravel, and with it went whatever remained of the enclosure.