The Ordnance Survey's 1836 edition marks this spot on the summit of a drumlin hill in Cornabaste, County Cavan, with the straightforward label 'Fort'. By the 1876 edition, that certainty had softened to 'Site of', a small cartographic admission that whatever had stood here was already gone, or at least no longer legible to anyone walking the ground.

The structure in question would have been a rath, the Irish term for a ringfort, which is a roughly circular enclosure defined by one or more earthen banks and ditches. Ringforts were the most common settlement type in early medieval Ireland, used as enclosed farmsteads from roughly the fifth to the twelfth centuries. They were typically built on elevated ground, and the choice of a drumlin summit here follows that logic precisely. Drumlins, the smooth oval hills formed from glacial deposits that give so much of Cavan and neighbouring counties their distinctive rumpled landscape, offered good drainage, a commanding view of the surrounding land, and a degree of natural defensibility. Whatever community or family built this particular enclosure would have looked out over a valley shaped entirely by retreating ice.

Today, nothing is visible at ground level. The site survives, if it survives at all, only as a faint subsurface trace, the kind of place that announces itself through crop marks in a dry summer or a slight unevenness underfoot, noticed only by someone who already knows to look.