Sister cities of Bilbao

Bilbao (/bɪlˈbaʊ/, /bɪlˈbɑːoʊ/; Spanish: [bilˈβao]; Basque: Bilbo [bilβo]) is a municipality and city in Spain, the capital of the province of Biscay in the autonomous community of the Basque Country. With a population of 353,187 as of 2010, it is the largest city of its autonomous community and the tenth largest in Spain. With roughly 1 million inhabitants, Bilbao lies within one of the most populous metropolitan areas in northern Spain. The Bilbao metropolitan area includes the comarca of Greater Bilbao (875,552) making it the fifth-largest urban area in Spain.

Bilbao is situated in the north-central part of Spain, some 14 kilometres (8.7 mi) south of the Bay of Biscay, where the estuary of Bilbao is formed. Its main urban core is surrounded by two small mountain ranges with an average elevation of 400 metres (1,300 ft).

Since its foundation in the early 14th century by Diego López V de Haro, head of the powerful Haro family, Bilbao was a commercial hub that enjoyed significant importance in the Green Spain, mainly thanks to its port activity based on the export of iron extracted from the Biscayan quarries. Throughout the nineteenth century and beginnings of the twentieth, Bilbao experienced heavy industrialisation which made it the centre of the second-most industrialised region of Spain, behind Barcelona. This was joined by an extraordinary population explosion that prompted the annexation of several adjacent municipalities. Nowadays, Bilbao is a vigorous service city that is experiencing an ongoing social, economic, and aesthetic revitalisation process, started by the iconic Bilbao Guggenheim Museum, and continued by infrastructure investments, such as the airport terminal, the rapid transit system, the tram line, the Alhóndiga, and the currently under development Abandoibarra and Zorrozaurre renewal projects.