The Casa Milà, popularly called La Pedrera, is a modernist building by the architect Antoni Gaudí, built between 1906 and 1910. The house was built by commission of the marriage Pere Milà i Camps and Roser Segimon i Artells, and Gaudí collaborated with his assistants Josep Maria Jujol, Domènec Sugrañes, Francesc Quintana, Jaume Bayó i Font, Joan Rubió, Enrique Nieto and Josep Canaleta, as well as the builder Josep Bayó i Font, who had worked with Gaudí in The Casa Batlló.
The Casa Milà reflects the artistic fullness of Gaudí: it belongs to its naturalistic stage (first decade of the 20th century).
Casa Milà was declared a Historical-Artistic Monument of National Character in 1969, and in 1984 the UNESCO included it in the World Heritage Site «Works of Antoni Gaudí», together with Palace Güell, Park Güell and the Crypt of the Colonia Güell.
The building was built on a land of 34 by 56 meters, with 1835 m2 of surface. It consists of six floors articulated around two inner courtyards, one circular and another oval, plus a basement, a loft and roof. This structure houses two semi-detached and independent buildings, each with its own access door and its own patio of lights, which are communicated only on the ground floor. However, the facade presents a unitary structure and common to both buildings. The building did not respect any conventional style, reason why it received many critics.