The final secular design of the Spanish surrealist Antoni Gaudí, Casa Milà Barcelona is an apartment building with a fanciful aura. Wavy walls made of rough-chipped stone suggest fossilized ocean waves. Doors and windows look like they are 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 (the Quarry). In 1984, UNESCO classified Casa Milà as a World Heritage site. Today, it is used mostly for cultural expositions.