Historically, Zagreb developed on two adjacent mountains. 1557 zagreb first appeared as the capital of Croatia. 1850, two hills were formally merged into a complete and unified city.
Zagreb plays an important role in Croatia's economic life. The main industrial sectors are petrochemical, electric power, medicine, machinery, electrical appliances and food processing. Famous large enterprises include Ina Oil Company, Keke Electric Power Company, Pliva Pharmaceutical Company and Conchar Electromechanical Company.
Zagreb is also one of the most important cultural, scientific and educational centers in Croatia. The University of Zagreb, founded in 1669, is one of the oldest institutions of higher learning in Europe. Zagreb is the twin cities of Shanghai, China.