Local tradition holds that the Brinny river did not always flow where it does today, and that at some point in the early nineteenth century, the watercourse was deliberately moved.

The bridge itself dates from the early nineteenth century and spans roughly 6.8 metres across the Brinny river at the point where it meets the Bandon. It is a hump-backed structure, meaning the roadway rises and falls in a gentle arc across the crossing rather than running level, and its three semicircular arches are flanked by pointed breakwaters, the angular projections built into a bridge pier to divide the current and reduce the force of water against the masonry. The bridge sits just to the north-west of Downdaniel Castle, and it is the castle that gives the local tradition its particular interest. According to that tradition, the Brinny once ran to the north of Downdaniel rather than to its present course to the south-west. If the diversion really did take place in the early nineteenth century, the construction of the bridge and the rerouting of the river may well have been connected undertakings, perhaps part of the same programme of estate improvement or road-making that reshaped so much of the Cork countryside during that period. Whether the river was moved to suit the road, the castle, or some other agricultural or drainage purpose, the tradition does not specify, and the physical evidence on the ground offers no easy answer.