In late 1883 Eusebi Güell added new land to the great estate that was his by inheritance, extending it as far as the former villages of Sarrià and Les Corts and turning it into a summer residence. The industrialist commissioned Gaudí to reform the family home and to build the estate’s boundary wall, including access gates and pavilions. This was the first cooperation of any scale between Güell and Gaudí, and was completed by the architect in 1887. The reform was lost between 1919 and 1924 when the house was converted into the new Royal Palace of Barcelona. Much of the estate's wall also disappeared as the city expanded, encroaching on the former Güell estate. But in spite of new urban developments, three secondary gates remain, along with the magnificent main entrance, flanked by one pavilion in the form of a porter's lodge and another for the stables and coach house
The Güell estate’s pavilions are minor masterworks in which Gaudí repeats the Neo Mudejar aesthetics of his youth but also introduces elements that would come to characterise his mature work like parabolic arches and vaults and hyperbolic domes. Among the most interesting ornamental aspects is the combined use on the exterior of brick, prefabricated cement panels and ceramic cladding. However, the most striking element is the wrought iron grille of the carriage entrance which represents one of the mythological passages of Atlàntida by poet Jacint Verdaguer, friend of Güell and Gaudí. This impressive grille reproduces Ladon, the mythological dragon who protected the golden oranges of the Garden of the Hesperides.