Provinces of Spain
In addition to its Autonomous Communities, Spain is divided into fifty provinces.
Formerly of greater importance, since the arrival of the autonomous community system the provinces have had fewer powers. They are still used as electoral districts, in postal addresses, phone codes, and as geographical referents. (A small town would be identified as being in Valladolid province rather than as being in Castile and Leon, for example.)
Most of the provinces are named after their principal town with the exception of Araba/Álava, Asturias, Bizkaia/Vizcaya, Cantabria, Gipuzkoa/Gipúzcoa, Illes Balears/Islas Baleares, La Rioja and Nafarroa/Navarra. There are only two cities that are capitals of autonomous communities without being capitals of provinces: Mérida in Extremadura and Santiago de Compostela in Galicia.
Seven autonomous communities are composed of only one province: Asturias, Balearic Islands, Cantabria, La Rioja, Madrid,Murcia, and Navarre.
http://en.wikipedia.org/wiki/Provinces_of_Spain