Iran has one of the highest urban population growth rates in the world. From 1950 to 2002, the urban proportion of the population increased from 27% to 60%.The United Nations predicts that by 2030 80% of the population will live in urban areas. Most internal migrants have settled near the cities of Tehran, Isfahan, Ahvaz, and Qom. Tehran, with a population of 8.2 million (2012 census), is the largest city in Iran and is the nation’s capital. Tehran is home to around 11% of Iran’s population. It is the hub of the country’scommunication and transport networks3
Mashhad, with a population of 2.7 million, is the second-largest Iranian city and the centre of the province of Razavi Khorasan. Mashhad is one of the holiest Shi’a cities in the world as it is the site of the Imam Reza shrine. It is the centre of tourism in Iran and between 15 and 20 million pilgrims go to Imam Reza‘s shrine every year
The third most populous city of Iran is Isfahan with a population 1.8 million (2011). This city is one of the most industrial cities of Iran with large industries. It has been designated by UNESCO as a World Heritage Site. The city also has a wide variety of historic monuments and is known for its paintings, history and architecture.
The fourth most populous Iranian city is Karaj, with a population of 1.6 million. Karaj is the capital of Alborz province and is situated 20 km west of Tehran, at the foot of Alborzmountains; however, the city is increasingly becoming an extension of metropolitan Tehran.