Aughnagan Ford, marked clearly on the Ordnance Survey six-inch map of 1843, has vanished entirely from the landscape. No stones, no shallow channel, no trace of a passage that was once considered significant enough to name and record.

The name itself is the most compelling thing that survives. According to the Ordnance Survey Name Books compiled around 1840, Aughnagan derives from the Irish Áth na gCeann, meaning Ford of the Heads. That kind of place-name, grim and unambiguous, almost always points to a specific violent event lodged in local memory, and here the tradition is explicit: a battle was fought at this crossing between Cromwellian forces and the O'Carroll army. The O'Carrolls were a Gaelic dynasty whose territory, Ely O'Carroll, covered much of what is now north Tipperary and south Offaly, and their resistance to Cromwell's campaign in Ireland during the early 1650s was part of a broader and brutal collapse of the old Gaelic order. Whether the heads in question belonged to one side or the other, the name suggests the ford was a place where the outcome was made visible and deliberate. The physical crossing itself was obliterated not by conflict but by industry: when the river level was raised to supply the mills at nearby Riverstown, the ford was drowned and lost.