Bucharest lies in the southeastern part of Romania, halfway between the Danube River and the Southern Carpathian Mountains on the banks of the Dîmbovita River. As the country's principal political, cultural and economic centre, it is at least five times larger than any other Romanian city. Urban Bucharest has more than doubled in population and land area since 1948 as a result of natural population growth, industrialisation and political centralisation. This has caused the city to become increasingly built-up and congested.