Viaduc de Neuvial, Railway viaduct in Bègues and Mazerier, France

The Neuvial Viaduct is a riveted steel railway viaduct on the Commentry–Gannat line, spanning a valley between Mazerier and Bègues. Its metal deck rests at each end on masonry abutments: the western one is a very large arch, the eastern one has two arches about ten metres high. A masonry pier and, mid-span, a metal pillar of four cylindrical columns braced by Saint Andrew's crosses carry the deck, and a separate metal span of different design links the pier to the eastern abutment.

The Compagnie du Paris-Orléans, taking over the western part of the planned Lyon-Bordeaux link, was the client; its chief engineer Wilhelm Nördling designed the viaduct. Construction was entrusted to Eiffel et Cie, founded by Gustave Eiffel in 1867, and the engineer who followed the works was his associate Théophile Seyrig. Built in 1869, it and the neighbouring Rouzat viaduct were the first railway viaducts erected by the firm, before the Maria Pia bridge in Porto (1877) and the Garabit viaduct (1884). It was listed as a monument historique on 8 December 1965, together with Rouzat.

The viaduct takes its name from the hamlet of Neuvial, part of Bègues, on the right bank of the Sioule. The D37 road from Gannat to Lalizolle loops beneath the structure twice, so drivers pass under the metal deck on a single stretch of road.

The D37 road from Gannat to Lalizolle, via Saint-Bonnet-de-Rochefort, loops at this spot and passes twice beneath the viaduct, so both banks can be reached by car. The structure is best read from below, where the masonry abutments, the central metal pillar and the riveted truss are all visible.

Neuvial and its neighbour Rouzat were the first railway viaducts built by Eiffel et Cie, founded in 1867, well before the Maria Pia Bridge in Porto (1877) and the Garabit Viaduct (1884). The designer was Wilhelm Nördling, chief engineer of the Paris-Orléans Company, while Théophile Seyrig followed the works on site.