Ostrava is the third largest city in the Czech Republic with population of 299 622 citizens (1. 1. 2012) and the second largest urban agglomeration after Prague. On the beginning of nineties Ostrava has 330.000 inhabitants, therefore the population is decreasing due not well economic situation and large unemployment and large pollution which has mainly harmful effect to the health of population. Ostrava is located close to the Polish border, it is also the administrative center of the Moravian-Silesian Region and of Ostrava-City District. It is part of the binational Upper Silesian metropolitan area.
Ostrava is located at the confluence of the Ostravice, Oder, Lučina and Opava rivers. Its history and growth have been largely affected by exploitation and further use of the high quality black coal deposits discovered in the locality, giving the town the look of an industrial city and the nickname of the “steel heart of the republic” during the communist era of Czechoslovakia. Many of the heavy industry companies are being closed down or transformed, yet the city remains one of the most polluted in the European Union.