A remarkable engineering structure on the line is the "Big Water of Fleet Viaduct", about a mile (2 km) north-east of the former Dromore station. It was the largest structure on the Portpatrick Railway, being a stone viaduct of twenty spans. In the early years of the twentieth century it was in danger of failing and extensive repair work was carried out from 1926, including sheathing the piers in heavy brickwork and spandrel strengthening using old rails; the repairs considerably degraded its aesthetic appearance. It is class B listed.