Mumbai, with an urban population of more than 12,000,000 people, is the largest city in India. It is a major center of world commerce and is home to the Reserve Bank of India (RBI), Bombay Stock Exchange (BSE), the National Stock Exchange of India (NSE) and the corporate headquarters of many Indian companies and numerous multinational corporations. Mumbai is a major international port and is one of the few major cities in the world to contain a national park. Sanjay Gandhi National Park is said to be "the lungs of Mumbai," as its lush forests help to purify the city's polluted air.
Mumbai is also home to Bollywood, the largest film industry center in the world. Bollywood is responsible for the production of well over 1,000 films per year,more than twice the output of Hollywood.