Today Madrid also serves as the commercial, cultural, and transportation center of Spain, as well as the capital of Madrid province.Surrounded by a rolling plateau, Madrid is located along the Manzanares River, a small tributary of the Tagus. The Sierra de Guadarrama, reaching 2,430 m (7,972 ft), overlooks the city in the north. Madrid's climate is marked by extremes: summers are hot, with an average temperature of 25 deg C (77 deg F) in July; in January the average temperature is 4 deg C (40 deg F). average annual rainfall is 406 mm (16 in) and falls mostly in the winter. Madrid is often subject to strong winds, which are dry and dusty in summer and piercingly cold in winter.CONTEMPORARY CITYThe center of Madrid, the old city, built around the original Moorish fortress, is characterized by narrow, twisting streets. Until 1868 this portion of the city was enclosed by walls, of which three gates still stand. Madrid's main thoroughfares radiate from the Plaza del Sol located in the old city. The modern city center lies to the east of the Moorish town. It is distinguished by wide, straight avenues and large plazas, the finest of which is the Plaza Mayor, built in the early 17th century. Many of the main public buildings are located along Paseo del Prado. Salamanca, a wealthy residential district, is located to the east. Ciudad Universitaria (university city) is in the northwest. Madrid's famous bull ring lies to the east of the city. Madrid has expanded rapidly in recent years by annexing nearby communities. Automobile pollution (especially during the summer) has become a serious problem.Madrid developed as an administrative, rather than an industrial, city. Today it is Spain's leading manufacturing center, but this is a recent development resulting from improvements in the national transportation system. Madrid is now the focus of a network of roads and railways that radiate to all parts of Spain. Industries include transportation equipment; textile, leather goods, chemicals, and plastics manufacturing; food processing; and mechanical and electrical engineering. Printing, publishing, and filmmaking are also important, and Madrid is the banking and financial center of Spain.The university of Madrid, established in Madrid in 1836, was moved to Ciudad Universitaria around 1920. The most famous of the many important museums located in Madrid is the Prado, one of the world's outstanding art museums, which has an outstanding collection of paintings by Spanish, Flemish, and Italian old masters. The Centro de Arte Reina Sofia (queen Sofia Arts Center), opened in 1986, is devoted to contemporary art.Other sites of interest include the Palacio Real, or Palacio Nacional (built 1737-64), the former palace of the Bourbon kings, which now houses a museum; the Biblioteca Nacional, which contains rare books and manuscripts; the Archaeological Museum, which maintains a large collection; and the San Isidro Cathedral, built during the 17th century. Madrid has splendid parks and open spaces, especially the botanical garden (founded 1781) and the parks located along the Manzanares River in the west and near the Prado in the east.HISTORYAlthough prehistoric and Roman remains have been found, Madrid was first mentioned in written sources during the 10th century. At that time it was called Majrit and was a Moorish fortress. In 1083, Majrit fell to Castile and became a Spanish fortress maintaining the frontier against the Moors. Occasionally it served as a meeting place for the Castilian court. In 1561, Philip II made Madrid his capital, and in 1607 it became Spain's permanent capital. It then began to grow rapidly. The court attracted many of Spain's leading artists and writers to Madrid, including Cervantes, Lope de Vega, and Velazquez. During the reign (1759-88) of Charles III, many of Madrid's finest buildings, including the Prado, were constructed. In 1808, during the Peninsular War, the French took Madrid. The French were driven out briefly by a popular uprising during the same year, but they returned and ruled the city until 1813. During the French occupation extensive building took place.Madrid was the major republican stronghold during the Spanish Civil War (1936-39). The city was besieged by Francisco Franco's Nationalist forces for two and a half years. When Madrid finally fell the civil war ended.Norman J. G. PoundsBibliography: Burns, Tom, Madrid (1988); Epton, Nina, Madrid (1964); Hills, George, The Battle for Madrid (1977); Launay, Andre, and Pendered, Maureen, Madrid and Southern Spain (1976); Levine, Robert, Madrid and the North of Spain (1988); Lyall, Archibald, Well Met in Madrid, rev. ed. (1960).