Drumlins, those elongated hills shaped by glacial movement, were favoured sites for early Irish ringforts, offering natural elevation and visibility without the need for dramatic cliff edges or river bends. This particular example belongs to a type known as a rath, an enclosed circular or oval settlement defined by an earthen bank and ditch, common across Ireland from roughly the early medieval period. What makes this one worth a second look is the layering of its defences: an inner bank separated from an outer field bank by a fosse, or ditch, with the arrangement shifting at the northern and north-eastern sides where the natural scarp of the drumlin itself takes over, making an artificial fosse unnecessary.

The rath at Nart is roughly subcircular in plan, measuring around 32 metres on its longer axis and 28.5 metres across. An entrance ramp on the eastern side, just under one and a half metres wide at its base, would have been the main point of access. Inside the bank at the southern end, a natural knoll adds a further irregularity to what might otherwise seem a straightforward earthwork. The site has been mapped consistently over two centuries: it appears on McCrea's Map of County Monaghan dated 1793, and again on the Ordnance Survey six-inch editions of 1834 and 1907, suggesting it was sufficiently visible and recognisable to cartographers across that entire period, even as the surrounding landscape changed around it.