Viaduc de Mussy-sous-Dun, Railway viaduct in Mussy-sous-Dun, France.

Viaduc de Mussy-sous-Dun is a railway bridge built to cross a valley in this rural part of Burgundy. It spans 561 meters in length and rises 60 meters high, with 18 rounded arches supporting the structure, each arch stretching about 25 meters across.

Construction started in March 1892 with the foundation laid on June 18, and the work was finished by August 1895. It was built to allow trains to travel along the line connecting Paray-le-Monial and Givors-Canal.

The viaduct is named after Mussy-sous-Dun, the small commune at its northern end, where the railway still has a stop before entering the 151-metre Tunnel de Mussy. The bridge crosses the valley of the Mussy, a tributary of the Sornin that joins the Loire at Pouilly-sous-Charlieu.

The structure is located at 91 La Roche in Mussy-sous-Dun and can be viewed from several spots on the ground around the area. Different viewpoints offer varying perspectives of the whole structure, so it is worth exploring the surroundings to find the best angle.

The two engineers behind the design were Jean Eugène Pouthier and Geoffry, the latter also responsible for the old Pont de la Jonelière in Nantes. The line was rebuilt from double to single track in 1997/98 because traffic had fallen, and the 151 m Tunnel de Mussy begins at the viaduct's northern end.