Although Karachi lost its crown as Pakistan’s capital to upstart Islamabad and the country’s cultural elite look towards Lahore, Karachi is the undisputed heart of the nation’s economy. A true world mega-city, greater Karachi is spread over an ever-expanding 3500 sq km, ­ perpetually sucking in workers from across the country. If you want to make it anywhere, the saying goes, you have to head for Karachi. As a result, Karachi is one of the most diverse and cosmopolitan cities in Pakistan, with ethnic Sindhis matched by large numbers of Punjabis, Pashtuns and other nationalities. After Partition, Karachi received significant numbers of Mohajirs, who have since become the key players in Karachi politics under the MQM party that dominates the city. Karachi also has significant Christian and Hindu communities, and is a centre for Zoroastrianism.