The longer of a pair of disused railway tunnels in Perth and Kinross, a half-mile (1 km) apart, Glenfarg South Tunnel is situated a quarter-mile (0.4 km) northwest of Bein Inn. Built in 1890 for the Inverkeithing & Perth Section of the North British Railway, which followed a difficult route through the Ochill Hills. The line remained in use until 1970 when it was sacrificed to allow the M90 motorway to occupy sections of the route. The tunnel remains extant, in good condition and is accessible.
Extending to 473m / 1551 feet, the tunnel was the work of William Galbraith (1829 - 1914), engineer to the North British Railway Company, and the contractor Glasgow-based Charles Brand & Sons. The tunnel is lined with concrete, a novel material at the time, but traditional dressed masonry was used for the portals.
