Karachi (Urdu:کراچی / ALA-LC: Karācī IPA:[kəˈrɑːˌtʃi]) is the largest city of Pakistan and the capital of the province of Sindh as well as one of the largest and most populous metropolitan cities in the world. It is also the main seaport and financial center of the country. Karachi metro has an estimated population of over 23.5million people as of 2013, and area of approximately 3,527km2 (1,362sqmi), resulting in a density of more than 6,000 people per square kilometre (15,500 per square mile).
Karachi is also ranked as a beta world city. It was the capital of Pakistan until Islamabad was constructed as a capital to spread development evenly across the country and to prevent it from being concentrated in Karachi. Karachi is the location of the Port of Karachi and Port Bin Qasim, two of the region's largest and busiest ports. After the independence of Pakistan, the city population increased dramatically when hundreds of thousands of MuslimMuhajirs from India and from other parts of South Asia came to settle in Karachi.