Photos

Much of the sediment clouding the water in this image of the Persian Gulf is from the Shatt al Arab River, which enters the Gulf in the north along the Iran-Iraq border. The river drains the combined waters of the Euphrates and Tigris Rivers of Iraq, and the Karun River of Iran. Though other rivers empty into the Persian Gulf, most of its fresh water comes from the Shatt al Arab. On the right edge of the image is the narrow Strait of Hormuz, which connects the Persian Gulf to the Arabian Sea, part of the northern Indian Ocean. The Persian Gulf is flanked to the west by wedge-shaped Kuwait and by Saudi Arabia with its vast tan-, pink-, and white-sand deserts; to the south by Qatar, the United Arab Emirates, and Oman; and to the east by the dry mountains of Iran. The wetlands and rivers of Mesopotamia border the Gulf on the north. The red dots mark gas flares in oil fields of Iran and Iraq. Image courtesy of NASA.

Measured by surface area, the Caspian Sea is the world's largest inland water body. It covers roughly 371,000 sq km (143,200 sq mi) and borders five countries. To the ancient Greeks and Persians, the lake's immense size suggested it was an ocean, hence its name. A large expanse of clear sky permitted this natural-color satellite image of the entire water body. The color of the Caspian Sea darkens from north to south, thanks to changes in depth and perhaps sediment and other runoff. The northern part of the lake is just 5 to 6 m (16 to 20 ft) deep. The southern end, however, plunges more than 1,000 m (3,300 ft). Just as the lake reaches a greater depth in the south, the nearby land reaches a greater height. The mountains of northern Iran line the southern end of the giant lake, and emerald green vegetation clings to those mountain slopes. In marked contrast to the mountains, sand seas line the southeastern and northern perimeters of the lake, and marshes occur along the lake shores in Azerbaijan to the west. Multiple rivers empty into the Caspian Sea, the Volga being the largest. Lacking an outlet, the Caspian Sea loses water only by evaporation, leading to the accumulation of salt. Although a lake, the Caspian is not a freshwater lake; the water delivered by the Volga River minimizes the lake's salt content at the northern end, but the Caspian grows more saline to the south. Kara-Bogaz-Gol is a saline inlet along the lake's eastern perimeter. Image courtesy of NASA.

In southwestern Iran, roughly 650 km (400 mi) south of the capital city of Tehran, and some 70 km (40 mi) northeast of Shiraz, a cultivated plain gives way to the Zagros Mountains. At the transition between flat land and rugged mountain, at the base of Kuh-i-Rahmat, or "Mountain of Mercy," lies Persepolis. Founded around 518 B.C. by Darius the Great, the site served as the ceremonial capital of the Achaemenid (or Persian) Empire. Image courtesy of NASA.

In this enhanced false-color satellite photo, shallow lakes, mudflats, and salt marshes share the sinuous valleys on Iran's largely uninhabited Dasht-e Kavir, or Great Salt Desert. Due to the high heat and arid climate, marshes, lakes, and wadis experience an extreme rate of groundwater evaporation leaving large crusts of salt. Image courtesy of USGS.

The Zagros Mountains in southwestern Iran present an impressive landscape of long linear ridges and valleys. Formed by collision of the Eurasian and Arabian tectonic plates, the ridges and valleys extend hundreds of kilometers. This astronaut photograph of the southwestern edge of the Zagros mountain belt includes another common feature of the region - a salt dome (Kuh-e-Namak or "mountain of salt" in Farsi). Thick layers of minerals such as halite (table salt) typically accumulate in closed basins during alternating wet and dry climatic conditions. Over geologic time, these layers of salt are buried under younger layers of rock. The pressure from overlying rock layers causes the lower-density salt to flow upwards, bending the overlying rock layers and creating a dome-like structure. Erosion has spectacularly revealed the uplifted tan and brown rock layers surrounding the white Kuh-e-Namak to the northwest and southeast (center of image). Radial drainage patterns indicate another salt dome is located to the southwest (image left center). If the rising plug of salt (called a salt diapir) breaches the surface, it can become a flowing salt glacier. Salt domes are an important target for oil exploration, as the impermeable salt frequently traps petroleum beneath other rock layers. Image courtesy of NASA.

The Shrine of Fatima Masumeh in Qom is considered to be one of the most significant Shi'a shrines in Iran and is visited by pilgrims from around the world. Qom, the capital of Qom Province and the seventh largest city in Iran, is the principle center for Shi’a scholarship in the world.

A view of the Elburz Mountains, a narrow mountain range that curves along the southern shore of the Caspian Sea in northern Iran. Trending west to east, the mountain range measures about 970 km in length and forms a climatic barrier between the Caspian and the Central Iranian Plateau.