Surat is the eighth largest city in India. The city proper is the seventh most populous city in India and 49th in the world. Surat is the administrative capital of Surat district. The city is situated on the left bank of the Tapti River, 14 miles from its mouth. The Population of Surat with its Twin City Navsari is above 6.3 million as of 2009. A moat divides the older parts of the city, with its narrow streets and handsome houses, and the newer suburbs. The city is largely recognized for its textile and diamond businesses. It is also known as the diamond capital of the world and the textile capital of India. 92% of the world's diamonds are cut and polished in Surat. Surat is also the third cleanest city in India after Chandigarh and Gandhinagar. Surat was once the largest city in India. It has one of the highest GDP growth rates in India at 11.5% as of 2008. Surat was the primary port of India during the Mughal period, a distinction it lost to Bombay during the British Raj.