The viaduct was completed in 1910, and crosses the Glen Road. It was originally part of the
Castleblayney, Keady and Armagh Railway, though services to Castleblayney were ended in 1924. Ultimately the Keady Viaduct carried trains for a mere 14 years. The line had been taken over by the
Great Northern Railway (Ireland) shortly after opening. In August 1993, Keady Viaduct became a Grade B listed building. == Design ==