Hyderabad ( ) is the capital and largest city of the Indian state of Telangana and the de jure capital of Andhra Pradesh. Occupying along the banks of the Musi River, it is located on the Deccan Plateau in the northern part of South India. With an average altitude of , much of Hyderabad is situated on hilly terrain around artificial lakes, including the Hussain Sagar lake, predating the city's founding, in the north of the city centre. According to the 2011 Census of India, Hyderabad is the fourth-most populous city in India with a population of 6.9 million residents within the city limits, and has a population of 9.7 million residents in the metropolitan region, making it the sixth-most populous metropolitan area in India. With an output of US$74 billion, Hyderabad has the fifth-largest urban economy in India.