Tehran is the capital and largest city of Iran. It is also the capital of Tehran province and the administrative center for Tehran County and its Cent…Tehran is the capital and largest city of Iran. It is also the capital of Tehran province and the administrative center for Tehran County and its Central District. With a population of around 9.8 million in the city, and 16.8 million in the metropolitan area, Tehran is the most populous city in Iran and Western Asia, the second-largest metropolitan area in the Middle East after Cairo, and the 24th most populous metropolitan area in the world. Greater Tehran includes several municipalities including, Karaj, Eslamshahr, Shahriar, Qods, Malard, Golestan, Pakdasht, Qarchak, Nasimshahr, Parand, Pardis, Andisheh and Fardis.