Tehran is the capital of Iran. Tehran is second-largest metropolitan area in the Middle East. According to the Global Destinations Cities Index in 2016, Tehran is among the top ten fastest growing destinations. The city can be roughly divided into two different parts - north and south. The northern districts of Tehran are more prosperous, modern, cosmopolitan and expensive while southern parts are less attractive but cheaper.
The settlement of Tehran dates back over 7,000 years. At the time of the Zand dynasty, it was a little town that was significant from a strategic point of view. The Qajar king Agha Mohammed Khan choose Tehran as the country's capital in 1778. And most of its growth started during the reign of a subsequent Qajar monarch, Fath-Ali Shah. The castle which Agha Mohammed Khan had built was to contain the new majestic buildings. The capital has been moved several times throughout the history, and Tehran is the 32nd national capital of Iran. During World War II, Soviet and British troops entered the city. In 1943, Tehran was the site of the Tehran Conference, attended by U.S. President Franklin D. Roosevelt, Soviet Premier Joseph Stalin, and British Prime Minister Winston Churchill.
Its population of around 8.8 million in the city and 15 million in the larger metropolitan area of Greater Tehran. Tehran is the most populous city in Iran and Western Asia. The majority of the population of Tehran are Persian-speaking people, and roughly 99% of the population understand and speak Persian, but there are large populations of other ethno-linguistic groups who live in Tehran and speak Persian as a second language. Iranian Azeris form the second-largest ethnic group of the city. The majority of Tehranis are officially Shia Muslims, which has also been the state religion since the 16th-century. Other religious communities in the city include followers of the Christian, Judaism, and Jews.
Tehran, as one of the main tourist destinations in Iran, has a wealth of cultural attractions. Tehran is home to many historical collections, including the royal complexes of Golestan, Sa'dabad, and Niavaran, where the two last dynasties of the former Imperial State of Iran were seated. Tehran's most famous landmark, the Azadi Tower, was built by the order of the Shah in 1971. There are several historic, artistic and scientific museums in Tehran. The Iranian Imperial Crown Jewels, one of the largest jewel collections in the world, are also on display at Tehran's National Jewelry Museum.
Tehran is served by the international airports of Mehrabad and Khomeini, a central railway station, the rapid transit system of Tehran Metro, a bus rapid transit system, trolleybuses, and a large network of highways. Tehran is one of the most car-dependent cities in the world. Tehran has a central railway station that connects services round the clock to various cities in the country, along with a Tehran–Europe train line also running.
Tehran is the largest and the most important educational center of Iran. There are a total of nearly 50 major colleges and universities in Greater Tehran. Among major educational institutions located in Tehran, Sharif University of Technology, University of Tehran, and Tehran University of Medical Sciences are the most prestigious.
A plan to move the capital has been discussed many times in prior years, due mainly to the environmental issues of the region. Tehran is rated as one of the world's most polluted cities, and is also located near two major fault lines. The city suffers from severe air pollution.
Tehran is the economic center of Iran. About 30% of Iran's public-sector workforce and 45% of its large industrial firms are located in the city, and almost half of these workers are employed by the government. Tehran's present-day modern industries include the manufacturing of automobiles, electronics and electrical equipment, weaponry, textiles, sugar, cement, and chemical products. It is also a leading center for the sale of carpets and furniture. The oil refining companies are based in Tehran.