Casa Mila, also known as “the Quarry" as it has rock-like façade, was Gaudi’s last private commission. Although the apartment building houses a few residences, most of the structure is open to visitors. There is a special exhibition housed in the attic of the Casa Mila, which includes models and explanations of all Gaudi’s projects. Especially interesting, is the wonderland of rooftop chimneys and staircases that visitors can pass through, while circling a large opening to the building’s central courtyard.

It is comparable to the steep cliff walls in which African tribes built their cave-like dwellings. The wavy facade, with its large pores, is reminder of an undulating beach of fine sand formed by a receding dune. The honeycombs made by industrious bees might also spring to the mind of the viewer while viewing the snake-like ups-and-downs that run through the whole building. In this last secular building which he constructed before devoting all his energies to the Sagrada Familia, Gaudi created a contradiction in terms - an artificial but natural building which was concurrently a summary of all the forms that he had since become famous for. The roof sports an imitation of the bench from Guell Park as well as an ever more impressive series of bizarre chimney stacks.

The building breaks with traditional architecture by using not a single straight line. It does not use load-bearing walls, but rest on pillars and arches. Together with the use of steel this allowed the architect to create completely irregular floor plans. Even the height of the pillars and ceilings differ from one to another. So as to allow light in all the rooms, the apartments are set around two central courtyards, one circular and the other oval shaped.

The top floor, attic and the extraordinary roof are open to visitors. The top of the apartment gives an idea of how the interior must have looked at the beginning of the 20th century. Just like on the outside, the interior has virtually no straight lines. The attractive rooms have a lot of character, with a mixture of expressionist and Art Nouveau styles. The attic houses an exposition of Gaudi’s works, with photos and scale models of his buildings. The roof is probably the most extraordinary of the building. It features a number of surrealistic colorful chimneys. Many of them look like warriors in a science fiction movie, while a few of them look frivolous. The roof also features a bench similar to the one in Park Guell. From the top of Casa Milà, one has a nice view over the Eixample district.

Casa Milà Barcelona is an apartment building with a fanciful impression. Wavy walls made of rough-chipped stone imply fossilized ocean waves, while doors and windows look like as if dug out of sand. A comical array of chimney stacks dances across the roof. This unique building is widely but unofficially known as La Pedrera or the Quarry. In 1984, UNESCO declared Casa Milà as a World Heritage site, and it is today used for cultural expositions.