A valley is a low area of land between hills or mountains, often formed by the erosion of soil and rock over time. Valleys can be created by various natural processes, including the movement of glaciers or rivers. They are typically characterized by their U-shaped or V-shaped profiles, depending on how they were formed. Valleys can be found in many landscapes around the world and are often home to rivers, lakes, and diverse ecosystems. They provide fertile land for agriculture and are important for wildlife habitats. Famous examples of valleys include the Great Rift Valley in Africa and the Yosemite Valley in the Sierra Nevada mountains of California.