Tow Bridge, Mary Street, Ballycastle, Co Antrim

The Tow Bridge is an 18th-century single-arch bridge situated on Mary Street in Ballycastle, County Antrim. It carries Mary Street over the Tow River and complements the pleasant promenade along the Margy river, exhibiting an unusual design.

The bridge features a single, almost semi-circular arch spanning 4½ metres, rising from low walls constructed of random rubble and lacking breakwaters. The riverbanks meet the rising walls of the bridge arch. The arch itself is built of robust pink sandstone voissoirs, and the spandrels on either side are slightly recessed, with a horizontal stringcourse at the top voissoir height creating a frame around the arch. The abutments, built of a mixture of basalt and sandstone in random rubble, extend significantly beyond the arch on the western side, connecting to the former harbour wall. The soffit of the vault is also constructed of random rubble.

While the precise date of construction is unknown, the bridge appears on the Ordnance Survey map of 1857 and is stylistically dated to the mid-19th century based on the dressed stone voissoirs of the arch. It is named on the Ordnance Survey map of 1904. An earlier crossing existed at this location, shown on an Ordnance Survey map of 1832, although not specifically mentioned in the OS Memoirs.

The bridge is considered to be of industrial archaeological interest and is located within a conservation area. It holds local historical interest and is owned by central government. The bridge’s architectural merits lie in its style, proportion, ornamentation, and structural system.