Casa Mila, Barcelona, Spain

Barcelona (English /bɑrsɨˈloʊnə/, Catalan: [bərsəˈɫonə], Spanish: [barθeˈlona]) is the capital of Catalonia and the second largest city in Spain, after Madrid, with a population of 1,620,943 within its administrative limits on a land area of 101.4 km² (39 sq mi). The urban area of Barcelona extends beyond the administrative city limits with a population of around 4.5 million within an area of 803 km² (310 sq mi), being the sixth-most populous urban area in the European Union after Paris, London, the Ruhr, Madrid and Milan. About five million people live in the Barcelona metropolitan area. It is also the largest metropolis on the Mediterranean Sea. It is located on the Mediterranean coast between the mouths of the rivers Llobregat and Besòs and is bounded to the west by the Serra de Collserola ridge (512 metres (1,680 ft)).

Casa Milà (Catalan pronunciation: [ˈkazə miˈɫa]), better known as La Pedrera (pronounced: [ɫə pəˈðɾeɾə], meaning the 'The Quarry'), is a building designed by the Catalan architect Antoni Gaudí and built during the years 1906–1912. It is located at 92, Passeig de Gràcia (passeig is Catalan for promenade) in the Eixample district of Barcelona, Catalonia, Spain.

It was a controversial design at the time for the bold forms of the undulating stone facade and wrought iron decoration of the balconies and windows, designed largely by Josep Maria Jujol, who also created some of the plaster ceilings.

Architecturally it is considered an innovative work for its steel structure and curtain walls – the façade is self-supporting. Other innovative elements were the construction of underground car parking and separate lifts and stairs for the owners and their servants.

In 1984, it was declared a World Heritage site by UNESCO. The building is made open to the public by the CatalunyaCaixa Foundation, which manages the various exhibitions and activities and visits to the interior and roof.