Casa Milà, popularly known as La Pedrera or "open quarry", a reference to its unconventional rough-hewn appearance, is a modernist building in Barcelona, Catalonia, Spain. It was the last private residence designed by architect Antoni Gaudí and was built between 1906 and 1910. The building was commissioned in 1906 by businessman Pere Milà and his wife Roser Segimon .