RED ARCH, RED BAY TL, Ballymena, CO.ANTRIM

Red Arch is a road tunnel constructed in 1817 through an Old Red Sandstone headland at Red Bay on the County Antrim coast, near Ballymena. It is a well-preserved early example of such a structure—road tunnels being rare in the Province compared with railway tunnels.

The tunnel was cut by Francis Turnly, a prominent local landowner based at Drumnasole near Carnlough, as part of a road improvement scheme. Before its construction, the route between Waterfoot and Cushendall lay to the west via what is now Middlepark Road, a steep and narrow road ascending over the headland. Turnly's new road allowed a more direct coastal route. The significance of this work is evident in the fact that his stretch of road was incorporated into the new Antrim Coast Road some twenty years later. Turnly was also responsible for another road improvement scheme, Turnly's Cut, north of Garron Point.

The tunnel has a parabolic profile and cuts through the headland directly above the pier on the northern shore of Red Bay. According to the 1835 Ordnance Survey Memoir for Layd Parish, the tunnel measures 36 feet long, 22 feet wide, and 30 feet high, and was described at that time as "a very pleasing and picturesque feature." The bare rock is exposed at the abutments, though the soffit and arch ring have been consolidated with cement render to prevent rock falls. A modern pedestrian footpath has been constructed around the seaward end of the headland. The tunnel is cited as such on Ordnance Survey maps from 1832 onwards and appears as "Red Arch" on the 1973 edition.

The headland through which the tunnel passes lies directly above the pier on the northern side of Red Bay. The ruinous remains of Red Bay Castle, a Scheduled Monument, stand on the exposed headland above.

The tunnel is of structural and local interest and of industrial archaeological significance, testament to Turnly's foresight in improving communications and facilitating easier social and economic interactions for both himself and the local community.