Viaduc ferroviaire de Sully-sur-Loire, Railway bridge in Sully-sur-Loire, France.

The Sully-sur-Loire railway viaduct is a truss-girder bridge whose closed metal span, a lattice of crisscrossing diagonal bars, crosses the Loire on six pale stone piers plus two abutments. It links Sully-sur-Loire on the left bank with Saint-Père-sur-Loire on the right, 290 m downstream of the road bridge. Planned for double track, only the upstream half was built.

The viaduct was built between 1877 and 1880 by the company H. Joret et Cie. The Beaune-la-Rolande to Argent-sur-Sauldre line, via Sully-sur-Loire, opened in 1882 and used the bridge. In January 1985, when the road bridge 290 m upstream was destroyed by frost, a Bailey bridge was pushed onto the downstream side of the piers; it carried road traffic from March 1985 until September 1986.

The viaduct has been repurposed as part of the Loire cycling route, connecting travelers with the Renaissance castle and local communities. This transformation shows how industrial structures become gathering spaces for visitors and residents alike.

Walking across the viaduct provides views of the river and surroundings, though the metal surface can get warm in direct sunlight. Wear comfortable shoes and stay aware of cyclists sharing the path.

The deck was built for two tracks, but only the upstream half was ever laid. In January 1985, when cold destroyed the road bridge 290 m upstream, a Bailey bridge was pushed onto the downstream side of these piers; it carried cars until September 1986. The rails were lifted in 2019.