Valleys are a type of low-lying area that is surrounded by higher land. They are usually found in mountainous regions and are often the result of rivers that have been eroded over time. Valleys can be found all over the world, but they are most common in mountainous regions.
The most famous valley is the Grand Canyon, which is located in Arizona and stretches for miles across the Colorado Plateau. The Grand Canyon was formed by a river that flowed through it for millions of years before receding back to its current size. Other notable examples include Yosemite Valley, which is home to many waterfalls and natural attractions like El Capitan and Half Dome; the Dead Sea Valley, which sits on a fault line between Syria, Jordan, and Israel; and Lake Baikal Valley, which is located in Russia. In the past, the term “valley” was used only to describe a depression or hollow with a stream flowing through it. However, by evolving into different forms and assuming new meanings, valleys have been primarily associated with upland areas that are surrounded by mountains on all sides: they provide a sheltered and natural passage between two or more highland areas. In a valley with steep sides, there may be an escarpment where the slope is especially steep. In some valleys this is because of a fault that caused erosion and subsequence downcutting of the riverbed into the valley bottom, but in other cases there are no faults and it is due to other erosional processes such as bedload transport or surface runoff.