Alconetar Bridge - Construction Process - dailymotion

The Alconétar Bridge (Spanish: Puente de Alconétar), also known as Puente de Mantible, was a Roman segmental arch bridge in the Extremadura region, Spain. The ancient structure, which featured flattened arches with a span-to-rise ratio of 4–5:1, is one of the earliest of its kind.[1] Due to its design, it is assumed that the bridge was erected in the early 2nd century AD by the emperors Trajan or Hadrian, possibly under the guidance of Apollodorus of Damascus, the most famous architect of the time.[2]

The almost 300 m long Alconétar Bridge served as a crossing point for the Roman Via de la Plata, the most important north-south connection in western Hispania,[3] over the Tagus, the longest river of the Iberian peninsula. It presumably remained in service until the Reconquista, after which numerous early modern reconstruction attempts by Spanish engineers failed. The ruins, which were mainly to be found on the right river bank, were relocated from their original position in 1970 when the Alcántara reservoir was created.