Częstochowa is a city in southern Poland on the Warta River with a population of about 270,000 and an area of about 160 square kilometers. It has advanced chemistry, paper, and building materials industry (with limestone and marl as raw materials). As iron ore production in its vicinity reaches 90% of total production of the country, the city boasts large ore-dressing plants and steel works, making ferrous metallurgy industry its most important industry. In addition, it has the largest hemp-jute textile industry center in Poland.