Puente ferroviario Biobío, Railway bridge across Bío Bío River in Concepción, Chile

Puente Ferroviario Biobío is a steel railway bridge that crosses the Bío Bío River, linking Concepción with San Pedro de la Paz. The structure is composed of metal sections supported by multiple pillars, with a tunnel passing beneath Cerro Chepe before the bridge begins its span.

The bridge was built in 1889 by The Arauco Company Limited to connect Concepción with coal mines in Lota and the port of Coronel. This structure became essential for moving resources from mining areas to urban centers and shipping ports.

The bridge's name is tied to the Bío Bío River it crosses, and locals now call it the "antiguo Puente Ferroviario" after its closure on 4 July 2025. The last passenger train over it was the 22:45 Biotrén from Concepción to Coronel; the first crossing dated to 1890. Mayors of the region have proposed turning the disused viaduct into a pedestrian and cycling route over the river.

The bridge closed to rail traffic on 4 July 2025, when the last Biotren service crossed it at 22:45, and it has since been disconnected from the railway network. It is not open to pedestrians, and no official access or viewing point exists. Its future use, proposed as a pedestrian and tourist walkway, still depends on technical studies and funding.

The bridge's original structure had 62 steel spans of 25.531 m each, 61 piers of 4.26 m and 121 expansion joints totalling 7.44 m, giving a length of 1,859.92 m; some sources cite 1,886 m. The last passenger train crossed on 4 July 2025 at 22:45, bound from Concepción to Coronel, after 135 years of service.