Viaduc de Barajol, Railway bridge in Riom-ès-Montagnes, France.

The Viaduc de Barajol is a railway bridge in the Auvergne region that spans across a valley and rests on twelve arches. The structure uses grey gneiss and dark volcanic basalt stone sourced from the surrounding area.

The line from Bort-les-Orgues to Neussargues was decided in 1892 to open up northern Cantal, and crossing terrain above 800 m required five viaducts, Barajol among them. Winter conditions kept the intended Languedoc and Roussillon wine traffic to Paris from developing. Passenger service ended on 26 May 1990 and freight on 31 August 1991; the viaduct was listed as a monument historique in 1984.

The viaduct is the main attraction of the Gentiane express tourist railway, which runs over it between Riom-ès-Montagnes and the closed Condat - Saint-Amandin station. It has also served as a natural film set for cinema, TV game shows and several television series. It is also known as the "viaduc de Lune Sèche".

You can view the bridge best from ground level or from the sides of the valley to see its full height and span. The area has hiking paths and viewpoints that offer good vantage points.

The viaduct crosses the valley of the Petite Rhue, just above where the Grolle stream joins it; the river rises directly on the Puy Mary. The structure has also served as a natural set for films, TV game shows and several television series.