About 45 percent of Peru's inhabitants are Native Americans, some of whom are descended from the Inca who established a great civilization in the region by the 15th century. Some 37 percent of the country's people are mestizos, persons of mixed white (mainly Spanish) and Native American background. About 15 percent of Peruvians are of unmixed white descent, and many of the remainder are of black African extraction. About 70 percent of the people live in urban areas. Population Characteristics The population of Peru (1993 estimate) was 23,210,352, giving the country an estimated overall population density of about 18 people per sq km (about 47 per sq mi). The distribution, however, is uneven, with about 50 percent of the people inhabiting the sierra region and about 40 percent inhabiting the coastal plain. Political Divisions For administrative purposes, Peru is divided into 25 departmental capital councils. Principal Cities The largest city in Peru is Lima (population, 1989 estimate, 6,233,800), the country's capital and chief commercial center. Other important cities include Arequipa (612,100), an industrial center; Trujillo (513,200), a commercial center; Chiclayo (409,600), in the sugar district; and Cuzco (264,400), famous for its Inca ruins. In addition, Callao (1985 estimate, 512,200), near Lima, is a major port. Language and Religion Spanish, spoken by some 70 percent of the people, was the sole official language of Peru until 1975, when Quechua, one of the principal languages of the Native Americans, also was made an official language. English and Aymará, another Native American language, are also spoken. More than 90 percent of Peruvians adhere to the Roman Catholic religion. In accordance with a law passed in 1915, Roman Catholicism is the established religion of the country. Other religions are permitted and tolerated, and small numbers of Protestants, Jews, and Muslims live in Peru. Education The literacy rate in Peru has increased substantially as a result of greater emphasis on education. According to estimates, the adult literate population rose from 42 percent in 1940 to about 85 percent in the mid-1980s. Public basic education in Peru is free and compulsory for all children between the ages of 6 and 15. Many children in rural areas do not attend secondary school, however, because of a lack of facilities. In the late 1980s some 3.7 million pupils attended elementary schools, and about 1.7 million students were enrolled in secondary and vocational schools. Peru has more than 45 institutions of higher education, including the National University of San Marcos, in Lima (1551); the National University of Central Peru (1962), in Huancayo; the National University of San Agustín (1828), in Arequipa; the National University of San Antonio Abad (1962), in Cuzco; and the National University of La Libertad (1824), in Trujillo. The National Conservatory of Music (1908) is in Lima. Some 576,800 students attended institutions of higher education in the late 1980s. Culture The Native American heritage of Peru is one of the richest in South America. Although Spain gave Peru its language, religion, and rulers, the civilization of the Inca has left its traces throughout Peruvian culture. Archaeological excavations have uncovered monumental Native American remains. Architecture of the Spanish colonial period, a fusion of Spanish and Native American forms, is called Creole. In art today, the indigenist school pointedly interprets 20th-century Peru in a Native American mode. The Native American pentatonic musical scale is still used, as are ancient instruments such as conch shells, flutes, ocarina, and panpipes. The descendants of the Quechua and Aymará Native Americans populate the Andean highlands. Many do not speak Spanish and have preserved the customs and folklore of their ancestors. Along the coast and in the highland cities, the whites, mestizos, and blacks live in a modern Western style. In contrast to these settlements are the jungles of eastern Peru, where more isolated groups of Native Americans retain lifestyles similar to those of their ancestors. Libraries Some of the most important libraries in Peru are located in the larger cities and are affiliated with the major universities. Within the various libraries of the National University of San Marcos in Lima are more than 450,000 volumes. The National Library (1821), in Lima, houses more than 3.2 million books and other items. Museums Museums throughout the country display Peruvian art and archaeological artifacts. Notable museums include the Museum of Art, the Rafael Larco Herrera Archaeological Museum, the Javier Prado Natural History Museum, and the National Museum of Anthropology and Archaeology, all in Lima; the Military History Museum of Peru, in Callao; and archaeological museums in Arequipa, Cuzco, Huancayo, and Trujillo.