the largest aggregate of cities in Poland, its most important industrial and transportation center. Located in the wojewódz-two of Katowice in the Upper Silesian coal field, including its eastern (Dabrowa) part. Area, 790 sq km (within the borders of the Upper Silesian urban complex). Population, 1.8 million (1967). It consists of almost unbroken urban construction and includes 29 population centers, including the cities of Katowice, Zabrze, Bytom, Gliwice, Chorzów, Ruda-Sląska and Sosnowiec, Siemianowice, Ślaskie, Dabrowa Górnicza, Swiętochłowice, Myslowice, and Będzin and also workers’ settlements. Most of the total Polish output of coal (over 50 mines), production of steel, and also of zinc and lead are concentrated in the Upper Silesian agglomeration of cities. Machine production (especially metalconsuming kinds) is developed, as are the chemical, silicate-ceramic, and food industries.