Bridges with integral defensive structures were not unheard of in medieval and early modern Ireland, serving as control points where a toll could be collected, passage denied, or an armed presence maintained over a strategically important crossing. What makes this one easy to overlook is precisely that it has vanished so completely, replaced by infrastructure that gives no hint of what came before.

The clearest surviving description comes from the Reverend William Henry, who recorded the bridge in 1739 and noted that it was a stately structure with the tower positioned in the midst of it, the gate and guard room designed for the defence of the pass. Henry also observed that the tide flows up the river to this place, a detail worth pausing on. Ballina sits close enough to the Atlantic that the River Moy remained tidal at this point, meaning the bridge marked not just a road crossing but a boundary between salt and fresh water, between the navigable estuary and the river proper. That combination of tidal reach and a fortified tower suggests the crossing had genuine strategic value, controlling both overland movement and whatever came upriver with the tide. By the time Henry was writing in the mid-eighteenth century the bridge was apparently still standing, though it has since been entirely replaced.