Santiago Calatrava is a Spanish architect, engineer, sculptor and painter known for his sculptural bridges and buildings that blend advanced engineering with dramatic visuals. Calatrava studied architecture and structural engineering, receiving his PhD for a thesis on foldable frames. He established an architecture firm in 1981 that has offices in multiple cities. One of his earliest and most famous works is the Alamillo Bridge in Seville, built for Expo '92, which transformed bridge design into sculpture through its asymmetrical pylon structure. Calatrava's buildings also use natural, zoomorphic forms and his knowledge of engineering to create innovative structures in unique shapes.