Hyderabad (/ˈhaɪdərəˌbæd/ HY-dər-ə-bad; often /ˈhaɪdrəˌbæd/) is the capital of the southern Indian state of Telangana and de jure capital of Andhra Pradesh. Occupying 650 square kilometres (250 sq mi) along the banks of the Musi River, it has a population of about 6.7 million and a metropolitan population of about 7.75 million, making it the fourth most populous city and sixth most populous urban agglomeration in India. At an average altitude of 542 metres (1,778 ft), much of Hyderabad is situated on hilly terrain around artificial lakes, including Hussain Sagar—predating the city's founding—north of the city centre.