The Casa Milà, popularly known as "La Pedrera", is a modernist building designed by the architect Antoni Gaudí, built between 1906 and 1910 in the Eixample district of Barcelona, at number 92 Passeig de Gràcia.

The house was commissioned by the couple Pedro Milà y Camps and Roser Segimon, and Gaudí was assisted by his assistants Josep Maria Jujol, Domingo Sugrañes, Francesc Quintana, Jaume Bayó, Juan Rubió, Enrique Nieto and José Canaleta, as well as the builder Josep Bayó i Font, who had worked with Gaudí on the Casa Batlló.

Milà's plan was to build a large building, with the main floor as his own residence and the rest of the building to be rented out, which was common at the time. The ground floor, on the outside, was to be used for shops, the first of which was a tailor's shop opened in 1928. On 2 February 1906, the plans were presented to the Town Hall and planning permission was applied for.

The construction suffered several delays, as the building exceeded the height and width established in the municipal ordinances, for which Mr. Milà was fined several times. In addition, Gaudí abandoned the direction of the work in 1909 because of disagreements with the Milàs over the interior decoration. The relationship between Gaudí and Milà cooled, and the architect had to take the developer to court to collect his fees, which he donated to the Jesuits. To meet the payment, Mr Milà had to mortgage the house.

The building was constructed on a site measuring 34 by 56 metres, with a surface area of 1835 m2. It consists of six storeys arranged around two inner courtyards, one circular and the other oval, plus a basement, an attic and the roof. This structure houses two independent semi-detached buildings, each with its own entrance door and its own courtyard, which are connected only on the ground floor. However, the façade has a unitary structure common to both buildings.

The load-bearing structure consists of solid brick and stone columns. The dividing walls have no structural function, so their design varies from floor to floor. The inner structure of pillars and beams is connected to the outer stone structure by means of curved metal beams along the perimeter of each floor.