Pourrhis viaduct, Abandoned railway bridge in Binic-Étables-sur-Mer, France

The Pourrhis viaduct (or Sieurnes viaduct) is a railway bridge in Binic-Étables-sur-Mer, built by Louis Harel de la Noë for the Côtes-du-Nord railways. It has 10 arches, measures 91.8 m long and 16.9 m high, and carries a pyramid- or diamond-point-shaped escutcheon. It spans the Ponto valley, where the Vau Durand stream flows beneath it.

The viaduct was built by engineer Louis Harel de la Noë for the Côtes-du-Nord railway company on the Saint-Brieuc to Plouha line, opened on 20 June 1905 and called the "jewel of the first network". Five trains used it each year until the line closed in 1956. After nearly 50 years of closure it was cleared and secured in 2007 by the Association pour la réhabilitation du Viaduc des Pourrhis.

The viaduct is accessible on foot or by bike along a trail that follows the old railway embankment, and sturdy footwear is a good idea since the surrounding paths are unpaved dirt roads. The site has no visitor facilities on-site, so it is best to plan accordingly before arriving.

Louis Harel de la Noë gave this viaduct a detail found on none of his other structures: a shield shaped like a pyramid or a diamond point, set on the masonry. Look for it while crossing. The arches themselves were singled out as particularly carefully built.