Hyderabad is the capital of the southern Indian state of Telangana and de jure capital of Andhra Pradesh.[A] Occupying 625 square kilometers (241 sq mi) along the banks of the Musi River, it has a population of about 6.8 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. Hyderabad was historically known as a pearl and diamond trading center, and it continues to be known as the City of Pearls. Many of the city's traditional bazaars, including Laad Bazaar, Begum Bazaar and Sultan Bazaar, have remained open for centuries.