Gaudí's architectural masterpiece, La Pedrera (known formally as Casa Milà), was commissioned by a businessman in 1905–10 and is now a UNESCO-listed site. Its uneven grey stone facade, which wraps around the corner of Carrer de Provença, gives the building its nickname of La Pedrera (the Quarry). This top tier achievement of the famous architect showcases his innovative ideas of space, light, and the blending of function and decoration.