Antoni Gaudí who is celebrated today with a Google Doodle, created some of the most memorable architecture of the early 20th century. He crossed over flawlessly with both his residential and his public commissions. His design for a garden city as dreamed of by the urbanists of the end of the 19th century is an outstanding example of his work in Catalonia Spain. It anticipated and influenced many of the forms and techniques that were relevant to the development of modern construction used today.

Gaudí was born in 1852 in Reus, a small town south of Barcelona, and he died in a street accident in 1926. The intellectual context towards the end of the 19th century in Catalonia was marked by Modernisme, a movement that extended from around 1880 to the First World War, parallel to currents such as Naturalism, Arts and Crafts, and Art Nouveau. It was motivated by return to traditions as an expression of national identity, as well as by the introduction of modern techniques and materials. Modernisme differed from the other movements by becoming important for popular cultural identity. Gaudí's work represents the genius of the architect, expressing particular spatial qualities and plasticity in the undulating lines and harmonies of colours and materials in architectural surfaces and sculpted features.

His main undertaking is the church of Sagrada Familia, based on the Latin cross. The work had been started by architect Francesc de P. del Villar in 1882 in Gothic revival style. In 1883 Gaudì made fundamental changes to the first project and continued the work until his death. The crypt was built in 1884-89 and the Nativity facade finished in 1905. The four fantastic bell towers were finished in 1925-30. The transept elevation of the Passion was started in 1960, and construction of the church still continues.

The other buildings making up the World Heritage site are: Casa de Botines (1892), Casa Calvet (1898), the residential villa of Figueras, or Casa Bellesguard (1900) and Casa Batlló (1904-7), an urban residence in Barcelona.