Tehran, or Teheran, Iran, the nation's capital and largest city. It is in the north-central part of the country at the southern edge of the Elburz Mountains, some 70 miles (115 km) from the Caspian Sea. The northern section of the city has modern European-style buildings. In the older southern section there are narrow, crooked streets and mud houses. Maidan Sipah, the central square, is the site of the national bank and other government buildings.

Tehran is the trade center for a farming area that produces fruits, grain, cotton, and sugar beets. Nearly half of Iran's industrial plants are in Tehran. Manufactured articles include textiles, rugs, chemicals, tobacco products, drugs, and processed foods. Railways link the city with ports on the Caspian Sea and the Persian Gulf and with most of Iran's other major cities. Mehrabad Airport accommodates international flights.

Tehran is the center for higher education in Iran. Its institutions include the University of Tehran and Iran University of Technology.

Tehran was founded in the 12th century, but it remained a small village until 1785, when Agha Mohammed Khan, first ruler of the Kajar dynasty, chose it for his capital. The Kajars built elaborate palaces and gardens and the Imperial Mosque. Modernization of the city began in 1925, when Riza Khan Pahlavi overthrew the Kajars and began a program of citywide improvements. Shah Mohammed Riza Pahlavi, who came to power in 1941, used Iran's oil revenues to finance a major building program in Tehran during the 1970's. In 1979, after the shah was overthrown, Iranian militants seized the United States embassy in Tehran and held its personnel hostage. They were released after 444 days of captivity.

Population: 6,475,527.