Asia's rivers are the lifeblood of the continent. People depend on them for water, cleanliness, and food. They honor them in their religions. They take their waters to irrigate crops.

Two of Asia's most important rivers are the Tigris and Euphrates, which flow through Turkey, Syria, and Iraq. It was on the land between these rivers—called Mesopotamia—where the world's first civilizations developed.

People today still depend on these ancient rivers. More than 30 large dams have been built on the Tigris and Euphrates. The dams create reservoirs of fresh water and prevent cities such as Baghdad from being flooded.

A dam project in China has been the subject of much controversy. The Three Gorges Dam is currently under construction on the Yangtze River, which is important to agriculture in China. Supporters say the giant dam will ease devastating floods by controlling the water level of the Yangtze. Opponents say the project will adversely impact the environment and the roughly two million people who will have to move to make way for it.

The Yangtze flows through the most fertile region of China, plains called the Land of Rice and Fish. Heavy rains help crops such as rice grow.

The Mekong River is also important to agriculture, irrigating crops and infusing soil with silt. It flows for 2,600 miles (4,180 kilometers) from the snowy Tibetan plateau in western China to the shores of the South China Sea in Vietnam. The least developed of Asia's major rivers, it has few bridges and passes few industrial areas.

In China's Yunnan Province, the Mekong is white water as it tumbles through canyons up to 2 miles (3.2 kilometers) deep. Most bridges over the Mekong are simple—sometimes nothing more than a steel cable across which people slide like acrobats.

In the dry season (November to May), the river can drop 40 feet (12 meters), exposing rocks and sandbars. Summer monsoons replenish the river.

Perhaps the most spiritual river in Asia is the Ganges River. The Ganges flows through northern India and Bangladesh. People use the river for many daily chores, such as washing themselves or cleaning clothes or pots and pans.

But the Ganges serves a more important role for many Hindus, who say prayers and make offerings of flowers or food to it. Devout Hindus make pilgrimages to the city of Varanasi, where they believe they can wash away sickness and sin in the Ganges.

Drinking from the river and bathing in it cleanses the soul and leads to a better life, Hindus believe. When a family member dies, the body is cremated and the ashes are scattered on the river's waters.

Though revered by millions, the Ganges faces serious pollution problems, caused mainly by sewage and industrial waste.