A gorge is a narrow valley with steep, rocky walls located between hills or mountains. It is created by millions of years of erosion by a river and other forms of weathering. Gorges are formed due to water erosion, weathering, geologic uplift, or the movement and melting of glaciers. They are typically formed in areas composed of limestone rock. Gorges are usually located between mountains, hills, or near-desert plateaus, at the point where a river cuts a channel into the land. They are more common in dry areas because erosion is common in arid places. A gorge can also be formed when an earthquake causes geologic uplift. The term "gorge" was derived from the French word meaning "neck" or "throat". The Grand Canyon is the most well-known gorge in the world, which is located in the US state of Arizona and was formed by the Colorado River.