Valleys may arise through several different processes. Most commonly, they arise from erosion over long periods of time by moving water and are known as river valleys. Typically small valleys containing streams feed into … See more

Some of the first human complex societies originated in river valleys, such as that of the Nile, Tigris-Euphrates, Indus, Ganges, Yangtze, Yellow River, Mississippi, and arguably the Amazon. In prehistory, the rivers were used as a source of fresh water and food (fish and … See more

Numerous elongate depressions have been identified on the surface of Mars, Venus, the Moon, and other planets and their satellites and are known as valles (singular: 'vallis'). Deeper valleys with steeper sides (akin to canyons) on certain of these bodies are … See more

• NPS.gov, University of Wisconsin
• UWSP.edu, Glossary of Alpine Glacial Landforms See more

There are many terms used for different sorts of valleys. They include:
• Dell: A small, secluded and often wooded valley.
• Cove: A small valley, closed at one or both ends, in the … See more

Africa
• Albertine Rift
• East African Rift
• Ethiopian Rift Valley
• Great Rift Valley
• Nile Valley (Egypt/Sudan/Ethiopia/Uganda) See more

• Canyon – Deep ravine between cliffs
• Grass valley – Meadow within a forested and relatively small drainage basin See more