In Northern Ireland, the A7 is a major trunk road running 15.0 miles (24.1 km) from Downpatrick, through Crossgar and Saintfield, to Carryduff. Here the A7 joins the A24 (running from Newcastle) at an at-grade roundabout, and continues to Belfast. The section between Carryduff and Saintfield was constructed in the latter half of the 19th century, to bypass Ouley Hill, as the previous route along Old Saintfield Road/Killynure Road was proving too arduous for stagecoach horses.