The Cerdagne line in the Pyrénées-Orientales, stretching from Villefranche-de-Conflent to Latour-de-Carol, was officially opened on July 18, 1910, after more than a century of planning and development. This mountain railway, known for its challenging terrain, includes 650 engineering feats, such as 19 tunnels and two remarkable bridges. The line reached its final endpoint at Latour-de-Carol in 1927, with the highest station in France, Bolquère, situated at an altitude of 1,593 meters. The construction of this line was a significant engineering achievement, requiring careful planning and innovation to navigate the rugged Pyrenees. Two engineers played a crucial role in creating the most iconic structures on the line: Paul Séjourné and Albert Gisclard. Séjourné was responsible for the Séjourné Viaduct, a two-level stone bridge 217 meters long, featuring a central arch that spans 30 meters over the Têt valley at a height of 65 meters. The viaduct was built to bypass unstable ground on the steep slopes of the valley. Recognizing its historical and architectural significance, the viaduct was classified as a historical monument in 1994. Albert Gisclard designed the Gisclard Bridge, a suspended railway bridge 253 meters long, completed in 1908. This was the first of its kind in France, and it was constructed by the company of Ferdinand Arnodin based on Gisclard’s design from 1896. The bridge crosses the Têt River at a height of 80 meters and was designated a historical monument in 1997. However, the bridge’s opening was not without incident. On October 31, 1909, during final load tests before its scheduled opening on November 26, an accident occurred when wheel chocks were removed prematurely with passengers on board. The train accelerated uncontrollably and derailed, resulting in the death of Gisclard and five others. The opening was delayed by eight months, with the first commercial train crossing the bridge on July 18, 1910, in Gisclard’s absence. Today, the Gisclard Bridge remains in service and has undergone recent maintenance. In 2023, twelve of its load-bearing cables were replaced during a major construction project. The small yellow train that runs on the Cerdagne line continues to carry tourists in open wagons, traveling at speeds of less than 30 km/h. Passengers can enjoy breathtaking views of the 80 meters of open space beneath the tracks, a testament to the engineering marvels that made this railway possible.