Casa Milà, Barcelona, Spain.
It is the last civil work designed by Catalan architect Antoni Gaudí, built between the years 1906 and 1910. It was commissioned in 1906 by businessman Pere Milà i Camps and his wife Roser Segimon i Artells. Architecturally it is considered structurally innovative, with a self-supporting stone front and columns, and floors free of load bearing walls. Also innovative is the underground garage. In 1984 it was declared a World Heritage Site by UNESCO.
La Pedrera-Casa Milà 41.3952484 2.1615701