from Wikipedia Tehran:
Tehran (or Teheran) (tʰehˈɾɒn (help·info); Persian: تهران Tehrān) is the capital and largest city of Iran, and the administrative center of Tehran Province.
Most Iranian industries are headquartered in Tehran. The industries include the manufacturing of automobiles, electronics and electrical equipment, military weaponry, textiles, sugar, cement, and chemical products. It is also a leading center for the sale of carpets and furniture. There is also an oil refinery located in south of the city.
Tehran is a sprawling city at the foot of the Alborz mountain range with an immense network of highways unparalleled in Western Asia. It is also the hub of the country's railway network. Although a relatively new city that does not evoke the history of other Iranian cities such as Isfahan, Shiraz, or Tabriz, Tehran has numerous large museums, art centers, palace complexes and cultural centers.
In the 20th century, Tehran faced a large migration of people from all around Iran. Today, the city contains a mix of various ethnic and religious minorities, and is filled with many historic mosques, churches, synagogues and Zoroastrian fire temples.