Visit to the Posadas Bridge over the Guadalquivir with José Antonio Torroja, filmed on July 7th 2013, duration: 6´23´´. José Antonio Torroja Cavanillasis a doctor in civil engineering and bridge designer. Professor in Armoured Concrete and Pre-stressing at the Polytechnic University of Madrid’s School of Engineering, of which he was the manager from 1988 to 2000. He is the author of exceptional work such as the Róntegui bridge (1977), the international bridge over the Miño (1992) or the Tamaraceite Viaduct (1993). He chaired the professional association on several occasions and received the National Civil Engineering prize in 2006.