This is a list of the largest metropolitan areas in Spain by population. Estimates are from the following sources: * the "Functional Urban Areas" (FUAs) of the Study on Urban Functions of the European Spatial Planning Observation Network (ESPON, 2007) * the "Larger Urban Zone" (LUZs) of Urban Audit project (2004), supported by the European Union. Not all cities were included in this survey. * calculations by Francisco Ruiz from data of the Instituto Nacional de Estadística (2008 estimates). As well as "metropolitan area" data, Ruiz has produced larger conurbation data for some areas. The "conurbation" figure is used where available, and is cited as such; otherwise, the "metropolitan area" figure is used.