With an area of 1,648,000 square kilometers, Iran ranks sixteenth in size among the countries of the world. Iran is about one-fifth the size of the continental United States, or slightly larger than the combined area of the contiguous states of California, Arizona, Nevada, Oregon, Washington, and Idaho.
Located in southwestern Asia, Iran shares its entire northern border with the Soviet Union. This border extends for more then 2,000 kilometers, including nearly 650 kilometers of water along the southern shore of the Caspian Sea. Iran's western borders are with Turkey in the north and Iraq in the south, terminating at the Shatt al Arab (which Iranians call the Arvand Rud). The Persian Gulf and Gulf of Oman littorals form the entire 1,770-kilometer southern border. To the east lie Afghanistan on the north and Pakistan on the south. Iran's diagonal distance from Azarbaijan in the northwest to Baluchestan va Sistan in the southeast is approximately 2,333 kilometers.
Iran is one of the world's most mountainous countries. Its mountains have helped to shape both the political and the economic history of the country for several centuries. The mountains enclose several broad basins, or plateaus, on which major agricultural and urban settlements are located. Until the twentieth century, when major highways and railroads were constructed through the mountains to connect the population centers, these basins tended to be relatively isolated from one another. Typically, one major town dominated each basin, and there were complex economic relationships between the town and the hundreds of villages that surrounded it. In the higher elevations of the mountains rimming the basins, tribally organized groups practiced transhumance, moving with their herds of sheep and goats between traditionally established summer and winter pastures. There are no major river systems in the country, and historically transportation was by means of caravans that followed routes traversing gaps and passes in the mountains. The mountains also impeded easy access to the Persian Gulf and the Caspian Sea.
A series of massive, heavily eroded mountain ranges surround Iran's high interior basin. Most of the country is above 1,500 feet, one-sixth of it over 6,500 high. In sharp contrast are the coastal regions outside the mountain ring. In the north, the 400-mile strip along the Caspian Sea, never more than 70 miles wide and frequently narrowing to 10, falls sharply from the 10,000-foot summit to 90 feet below sea level. In the south, the land drops away from a 2,000 foot plateau, backed by a rugged escarpment three times as high, to meet the Persian Gulf and the Gulf of Oman
LAKES AND SEAS
The Caspian Sea The Caspian Sea, which is the largest landlocked body of water in the world (424,240 sq. km.), lies some 85 feet below the sea level. It is comparatively shallow, and for some centuries has bene slowly shrinking in size. Its salt content is considerably less than that of the oceans and though it abounds with fish, its shelly coasts do not offer any good natural harbours, and sudden and violent storms make it dangerous for small boats. The important ports on the Caspian coast are: Bandar Anzali, Noshahr, and Bandar Turkman.
Other Lakes Along the frontier between Iran and Afghanistan there are several marshy lakes which expand and contract according to the season of the year. The largest of these, the Seestan (Hamun-Sabari), in the north of the Seestan &Y Baluchistan province, is alive with wild fowl.
Real fresh water lakes are exceedingly rare in Iran. There probably are no more than 10 lakes in the whole country,
most of them brackish and small in size. The largest are: Lake Urmiya (area: 3,900-6,000 sq. km. depending on season) in Western Azerbaijan, Namak (1,806 sq. km.) in the Central province, Bakhtegan (750 sq. km.) in Fars province, Tasht (442 sq. km.) in Fars province, Moharloo (208 sq. km.) in Fars province, Howz Soltan (106.5 sq. km.) in Central province.
Persian Gulf: The Persian Gulf is the shallow marginal part of the Indian ocean that lies between the Arabian Peninsula and south-east Iran. The sea has an area of 240,000 square kilometres. Its length is 990 kilometres, and its width varies from a maximum of 338 kilometres to a minimum of 55 kilometres in the Strait of Hormuz. It is bordered on the north, north-east and east by Iran, on the north-west by Iraq and Kuwait, on the west and south-west by Saudi Arabia, Bahrain and Qatar, and on the south and south-east by the United Arab Emirates and partly Oman. The term Persian Gulf is often used to refer not only proper to the Persian Gulf but also to its outlets, the Strait of Hormuz and the Gulf of Oman, which open into the Arabian Sea