The Arabian Peninsula, Iraq, and Iran

​The region contains four main landforms: rivers, plains, plateaus, and mountains. The Tigris  and Euphrates rivers flow across a low, flat plain in Iraq. They join together before they reach the Persian Gulf. The Tigris and Euphrates are what are known as exotic rivers, or rivers that begin in humid regions and then flow through dry areas.

​The rivers create a narrow, fertile area, which in ancient times gave rise to the world’s first civilization. Many people found it to be an ideal place to settle so they could develop farming and domesticate animals. The area is called Mesopotamia, or the “land between the rivers.” The Tigris and Euphrates were also important for transportation and trade. Mesopotamia became a crossroads for trade between India, China, Egypt, and people living along the eastern Mediterranean. The rivers helped in water transportation of goods. 

​Most of this region has a desert climate. The desert can be both very hot and very cold. In the summer, afternoon temperatures regularly climb to over 100°F (38°C). During the night, however, the temperature may drop quickly. Nighttime temperatures in the winter sometimes dip below freezing.

​Rainfall supports vegetation in some parts of the region. Trees are common in mountain regions and in scattered desert oases. An oasis is a wet, fertile area in a desert that forms where underground water bubbles to the surface. Most desert plants have adapted to survive without much rain. For example, the shrubs and grasses that grow on the region’s dry plains have roots that either grow deep or spread out far to capture as much water as possible. Still, some places in the region are too dry.

​Water is one of the region’s two most valuable resources. However, water is very scarce, or limited. The unequal distribution of water impacts irrigation and the availability of drinking water. In some places in the desert, springs provide water. At other places, water comes from wells dug into dry streambeds called wadis. Modern wells can reach water deep underground called fossil water. Fossil water is water that is not replaced by rainfall. Farmers modify the environment by using fossil water. Wells that pump fossil water will eventually run dry. 

​As the name suggests, Central Asia lies in the middle of Asia. All of the countries in this region are landlocked. Landlocked means completely surrounded by land with no direct access to the ocean. This isolated location is just one challenge presented by the physical features of the region.

​Much of Central Asia has a rugged landscape. In the south, many high mountain ranges, such as the Hindu Kush, stretch through Afghanistan. Tajikistan and Kyrgyzstan are also very mountainous. Large glaciers are common in high mountains such as the Pamirs.

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​Like its landlocked location, Central Asia’s rugged terrain presents a challenge for the region. Throughout history, the mountains have made travel and communication difficult and have contributed to the region’s isolation. In addition, tectonic activity causes frequent earthquakes there.

​From the mountains in the east, the land gradually slopes toward the west. There, near the Caspian Sea, the land is as low as 95 feet (29 m) below sea level. The central part of the region, between the mountains and the Caspian Sea, is covered with plains and low plateaus.

The plains region is the site of the fertile Fergana Valley. This large valley has been a major center of farming in the region for thousands of years.