Mulligan's Bridge, Drone Hill Road, Corbett, Banbridge, Co Down, BT32

Mulligan's Bridge is a triple-arch masonry road bridge built in 1826 over the River Bann at Corbett near Banbridge. It exemplifies the plain, functional style typical of early 19th-century bridge design and represents an important phase in the development of local infrastructure.

The bridge is constructed throughout of quarried random rubble blackstone. The three piers are finished with angled cutwaters of regularly-coursed dressed granite blocks, rising to arch spring level. The arches themselves are of segmental profile, with the middle arch slightly higher and wider than the end ones. All three arches are embellished with dressed granite voussoirs. Slit drain holes pierce the spandrels above the piers on both faces of the bridge.

Structural reinforcement has been added to the left-bank arch, with steel plates affixed to the voussoirs and steel bars installed under its soffit. Tie bars also pass through the spandrels at this end. The parapets are coped with roughly-dressed blackstone blocks. A stone plaque set into the upstream (east) parapet reads "Mulligan's Bridge / Built / AD 1826 / by P. & R. Byrne". A second plaque, added by the Annaclone Historical Society, details the bridge's history and is mounted on the downstream (southwest) face of the parapet.

The carriageway is slightly curved and measures one-and-a-half lanes wide, with dogleg approaches. A wooden depth gauge is mounted on the northeast abutment. According to the 1837 Ordnance Survey Memoir for Seapatrick Parish, the bridge measures 65 feet long and 15 feet broad and cost 330 pounds in Irish currency, financed by the County Down Grand Jury. The materials—granite and whinstone—were procured locally. The structure was likely promoted by Messrs Byrne, who probably financed it through the Grand Jury scheme.

The bridge is named after the Mulligan family, who also owned a beetling mill located just beyond the southeast end of the bridge; the mill buildings have since been refurbished for agricultural use. On the upstream side of the right (north) bank, a public amenity area with timber steps down to the water provides access for launching canoes.