Iran, officially the Islamic Republic of Iran, country in southwestern Asia, located on the eastern shore of the Persian Gulf.

One of the world's most mountainous countries, Iran contains Mount Damāvand, the highest peak in Asia west of the Himalayas.

The country’s population, while ethnically and linguistically diverse, is almost entirely Muslim. For centuries, the region has been the center of the Shia branch of Islam (see Shia Islam).

Iran ranks among the world’s leaders in its reserves of oil and natural gas. As is the case in other countries in the petroleum-rich Persian Gulf region, the export of oil has dominated Iran’s economy since the early 20th century

Iran lies at the easternmost edge of the geographic and cultural region known as the Middle East. The country is bordered on the north by Armenia, Azerbaijan, the Caspian Sea, and Turkmenistan; on the east by Afghanistan and Pakistan; on the south by the Gulf of Oman, the Strait of Hormuz, and the Persian Gulf; and on the west by Iraq and Turkey. Iran’s capital and largest city is Tehran, located in the northern part of the country.

Iran is the second largest country in the Middle East, after Saudi Arabia. It extends over a total area of 1,648,000 sq km (636,300 sq mi). The country is roughly triangular in shape, with its longest side extending in a slightly outward arc for 2,500 km (1,600 mi) from the border with Turkey in the northwest to the border with Pakistan in the southeast. The third point of the triangle lies in the northeast, about halfway along Iran’s border with Turkmenistan. Iran’s greatest extent from north to south is 1,600 km (1,000 mi) and from east to west is 1,700 km (1,100 mi).

More than half of Iran's international border of 4,430 km (2,750 mi) is coastline, including 740 km (460 mi) along the Caspian Sea in the north and 1,700 km (1,100 mi) along the Persian Gulf and adjacent Gulf of Oman in the south. Both the Caspian Sea and the Persian Gulf have important ports and contain extensive underwater deposits of oil and natural gas. Iran's largest harbor, Bandar-e ‘Abbās, is located on the Strait of Hormuz, the narrow passage separating the Persian Gulf and the Gulf of Oman.

Iran's extensive petroleum and natural gas deposits are located primarily in the southwestern province of Khuzestan and in the Persian Gulf. Iran also has one of the world's largest reserves of copper; deposits are located throughout the country, but the major lode lies in the central region between the cities of Yazd and Kerman. This region also serves as a center for the mining of bauxite, coal, iron ore, lead, and zinc. Additional coal mines operate throughout the Elburz Mountains; iron ore mines also exist near Zanjan in the northwest, near Mashhad in the northeast, and on