Officially known as Casa Milà, also known as the Milà House, after the man who commissioned the project, this building is called La Pedrera - The Quarry - by the locals because of its uneven stone exterior. One of Gaudí's several works dotting the city (another of which he never completed), La Pedrera was started as a dual apartment and office block for the bourgeoisie, on one of the main thoroughfares, Passeig de Gracia.
Though unfinished, the structure is a popular tourist attraction, where you can visit a floor decorated as it would have been by one of the wealthy couples who were to live there. The biggest draw to La Pedrera is the rooftop, where stand several impressive chimney pots shaped into what look like medieval knights. People pay the entry fee just to photograph and get an close look at these mysterious figures. A fascinating structure, La Pedrera is recognized both as a symbol of the ridiculous opulence of the Catalan elite as well as one of Gaudí's most interesting works.