Chennai, capital of Tamil Nadu, is one of India's five leading metropolises. It is the fourth largest city in India and the major industrial, business, and cultural center of South India. Chennai, formerly known as Madras, is the capital city of Tamil Nadu. It is located on the shore of the Bay of Bengal, about 900 miles north of the Equator. A city of 70 square miles (180 square km) and over 10 million people (the last census was in 1991); Chennai is one of India's five leading metropolises. It is the fourth largest city in India and the major industrial, business, and cultural center of South India. Forbes magazine named Chennai as one of the fastest growing cities in the world. Chennai is ranked 4th in India having the greatest number of Fortune 500 companies, coming after Mumbai, Delhi, and Kolkata. Chennai is the home to twenty four Indian companies that have a net worth of over $1 billion and has a diversified economic base anchored by the automobile, software services, hardware manufacturing, healthcare, and financial services industries.