That uncertainty is not down to careless record-keeping but to the particular way the Irish midlands were remade by engineering in the nineteenth century, erasing evidence that had survived for centuries beforehand.

The bridge appears on the Down Survey, a remarkable cartographic project carried out between 1656 and 1658 under the direction of William Petty, which mapped Irish land ownership in the aftermath of the Cromwellian conquest. On the Down Survey map of Carrigallen barony, a crossing is shown connecting the townland then recorded as Tumanahan, corresponding to the area known as Woodford, with County Cavan on the far side. The bridge sat close to a castle whose remains have been separately recorded. Whether it was a stone arch or a timber structure, how wide it was, and precisely who used it to cross between the two counties, the map does not say. What is certain is that by the time anyone thought to look carefully for physical remains, the ground had already been fundamentally altered. The Ballinamore and Ballyconnell Canal, constructed in the mid-nineteenth century to link Lough Erne with the Shannon navigation, cut through this stretch of river and severed a northward loop of the waterway in doing so. That loop is now the most plausible candidate for where the bridge once stood, the canal having rerouted the channel and almost certainly obliterated whatever masonry or timberwork once carried travellers across it.