Engineer Carlos Fernández Casado Bridge, Cable-stayed bridge in León, Spain

The Engineer Carlos Fernández Casado Bridge is a cable-stayed bridge over the Barrios de Luna Reservoir, carrying the AP-66 motorway. Two light-grey concrete pylons, joined by a crossbeam near the top, rise over 100 metres and divide the 643-metre deck into spans of 66, 440 and 66 metres. From each pylon, 220 thin cables fan down to the 22-metre-wide roadway, which has low parapets along both edges.

The structure was completed in 1983 and gained worldwide attention as the longest cable-stayed main span at that moment. This achievement marked a turning point in bridge engineering, demonstrating that such distances could be successfully achieved.

The bridge is named after Carlos Fernández Casado (1905–1988), a Spanish bridge engineer, though it was designed by Javier Manterola. Spain's Ministry of Public Works chose the name to honour Fernández Casado's career, which has led to some confusion over who actually designed the structure.

The bridge carries the AP-66 motorway over the Barrios de Luna Reservoir; there is no pedestrian access, so it is seen only in passing by car. The deck runs between the two pylons, and the central span is joined by a hinge at mid-point. Views of the towers and cables open from the reservoir shores and the surrounding roads.

The bridge is named after Carlos Fernández Casado (1905–1988), but it was designed by Javier Manterola, which has caused some confusion over the authorship. The Ministry of Public Works chose the name to honour Fernández Casado's career in bridge engineering. A joint sits at the centre of the 440-metre main span.