Surat is an Indian port city previously known as Suryapur. It is the economic capital and former princely state in the Indian state of Gujarat. It is the eighth largest city and ninth largest urban agglomeration in India. Surat is the 3rd "cleanest city of India" according to the Indian Ministry of Urban Development, and 4th fastest growing city of the world. Surat is famous for its food, textile, and diamonds. Surat polishes over 90 percent of the world's rough diamond. It is the administrative capital of the Surat district. The city is located south of the state capital, Gandhinagar; south of Ahmedabad; and north of Mumbai. The city centre is located 22km south of the Tapti River. A moat divides the older parts of the city, with their narrow streets and historical houses, from the newer suburbs.Surat had a population of 4.5 million at the 2011 census, making it the second largest city in the state of Gujarat, after Ahmedabad. It is the eighth largest city and ninth largest urban agglomeration of India. Surat is the 34th-largest city by area and 4th-fastest developing cities in a study conducted by the City Mayors Foundation, an international think tank on urban affairs. The city registered an annualised GDP growth rate of 11.5 per cent over the seven fiscal years between 2001 and 2008. Surat was awarded "best city" by the Annual Survey of India's City-Systems (ASICS) in 2013. Surat is selected as the first smart IT city in India which is being constituted by the Microsoft CityNext Initiative tied up with IT services majors Tata Consultancy Services and Wipro. The city has 2.97 million internet users which is about 65% of total population. Surat was selected in 2015 for an IBM Smarter Cities Challenge grant. Surat has been selected as one of twenty Indian cities to be developed as a smart city under PM Narendra Modi's flagship Smart Cities Mission.