Casa Mila, also known as La Pedrera, meaning the 'The Quarry', is a building designed by the Catalan architect Antoni Gaudi. It is located at 92, Passeig de Gracia in the Eixample district of Barcelona, Catalonia, Spain.

It was a controversial design at the time for the bold forms, undulating stone facade and wrought iron decoration of the balconies and windows, designed largely by Josep Maria Jujol, who also created some of the plaster ceilings.

Architecturally it is considered an innovative work for its steel structure and curtain walls, the facade is self-supporting. Other innovative elements were the construction of underground car parking and separate lifts and stairs for the owners and their servants. Gaudi also wanted the people who lived in the flats to all know each other. Therefore there were only lifts on every second floor so people had to communicate with one another on different floors.

In 1984, it was declared World Heritage by UNESCO. The building is made open to the public by the CatalunyaCaixa Foundation, which manages the various exhibitions and activities and visits to the interior and roof.

In this last secular building which he constructed before devoting all his energies to the Sagrada Familia, Gaudi created a paradox: an artificial but natural building which was simultaneously a summary of all the forms that he has since become famous for. The roof has an imitation bench from Guell Park as well as an ever more impressive series of bizarre chimney stacks.