That circularity is quietly melancholy: a place named after a monument, the monument gone, the name all that persists. Cairns, typically mounds of heaped stone marking a burial or a boundary, were once common features of the Irish landscape, many of them raised during the Bronze Age. This one sat on top of a drumlin, the low rounded hill formed by glacial drift that gives so much of the Monaghan landscape its rolling, humped character.

Ordnance Survey maps from 1834 and 1907 both recorded the feature, noting it in two different typographic conventions, italic lettering on the earlier edition and gothic script on the later one. When field workers described it in 1948, they recorded an elliptical mound, oriented roughly south to east, rising only about two feet above the surrounding ground, with a shallow depression at its centre. That sunken centre is a detail worth pausing on: it suggests the mound had already been disturbed at some point, whether by earlier excavation, by the collapse of a burial chamber beneath, or simply by the slow settlement of centuries. Whatever its origins, it was gone entirely by 1967, levelled at some point in the two decades after it was last formally recorded.