But what looks like a minor earthwork, a gentle depression perhaps 165 metres long with low rises of ground on either side, is in fact a surviving stretch of an ancient road that once led to one of early medieval Ireland's assembly sites on the shores of Lough Derg. The trackway runs in a roughly north-north-east to south-south-west direction, and where its flanking banks and boulder-set fences have been worn down by centuries of agriculture and weather, the sunken way itself, known as 'Cladh na Leac', persists as a legible line across the landscape.

The road is associated with the Oenach of Clochair, a ceremonial gathering or assembly, the kind of periodic event at which early Irish communities conducted trade, legal business, and ritual, held on the shore of Lough Derg. A reference to it appears in the poem of Guaire Dall, a text translated from the 12th-century Book of Leinster. In 1919, a researcher named Lynch recorded that he had traced what he called 'the great northern road' as far as a megalithic tomb known as Leaba na muice, which lies some 315 metres to the north-north-east of the trackway. By 1927, the Ordnance Survey was annotating the route on its six-inch maps, and the same edition recorded a standing stone on the eastern side of the road, noted only as 'Pillar (site of)', and a nearby feature called 'The Heroes Grave'. A description from 1944, by O'Kelly, gives a clearer sense of what the road once looked like: a sunken way bordered on each side by low fences with boulders placed at intervals, fading out at its northern end near a field at the north-west corner of the lake, and tapering off to the south just beyond the tumulus of the Heroes Grave. The church and graveyard of Mainister na Galliagh, the Monastery of the Nuns, lies about 190 metres to the east, and a megalithic structure recorded as a Giant's Grave stands some 210 metres to the south.

The trackway is visible on Ordnance Survey aerial photography as a linear feature crossing the fields, which offers the clearest sense of its full extent. On the ground, the hollow way is subtle enough that knowing what to look for matters considerably. The flanking banks are much degraded, presenting themselves as little more than a gentle rise on either side of the sunken centre. The concentration of ancient monuments in the immediate vicinity, the tomb, the assembly association, the ecclesiastical site, and the roadway itself, suggests this was once a genuinely significant corridor through the landscape, one that has been quietly dissolving back into the fields for several centuries.