Bilbao

Bilbao is located in the north-central part of Spain, some 16 kilometres (10 mi) south of the Bay of Biscay, where the economic social development is located, 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). Its climate is shaped by the Bay of Biscay low-pressure systems and mild air, moderating summer temperatures by Iberian standards, with low sunshine and high rainfall. The annual temperature range is low for its latitude.

After its foundation in the late 13th century by Diego López V de Haro, head of the powerful Haro family, Bilbao was one of the commercial hubs of the Basque Country that enjoyed significant importance in the Crown of Castile. This was due to its thriving port activity based on the export of wool and iron commodities extracted from the Biscayan quarries to all over Europe.

Throughout the nineteenth century and the beginning of the twentieth, Bilbao experienced heavy industrialisation, making it the centre of the second-most industrialised region of Spain, behind Barcelona. At the same time an extraordinary population explosion prompted the annexation of several adjacent municipalities.