an administrative and territorial unit in western Bulgaria. Area, 7,400 sq km. Population, 326,000 (1974). The administrative center is the city of Sofia, which administratively is not part of the district. The northern part of the district is occupied by part of the Stara Planina (Balkan Mountains), the south by the Rila Mountains, and the east by the Sredna Gora. The bulk of the population is concentrated in intermontane basins, of which the Sofia Basin is the largest. There are deposits of coal (mainly brown coal), complex ores, and copper ores.
Sofia District has an industrial and agrarian economy; the ratio of the gross industrial output to the gross agricultural output was 43:57 in 1959 and 81:19 in 1973. The main branches of industry are nonferrous metallurgy (for example, a copper combine near Zlatitsa), the coal and chemical industries (concentrated in Kostinbrod and Kostenets), the forestry and textile industries (concentrated in Samokov and other cities), and the food-processing industry (concentrated in Svoge). Machine building is developing rapidly, including electrical engineering (especially in Botevgrad, Godech, and Slivnitsa). There is a cast iron plant in the city of Ikhtiman. Livestock raising accounts for more than one-half of the agricultural output, and meadows cover approximately one-fourth of the agricultural area. Sofia District has more cattle and produces more flax than any other district in Bulgaria. A tourist center, the district has several mountain health resorts, for example, in Borovets.
E. B. VALEV