A canyon is a deep, narrow valley with steep sides, often formed by the erosion of rock and soil over time, typically by a river. Canyons can vary in size and shape, and they are commonly found in mountainous regions. Famous examples include the Grand Canyon in the United States and the Colca Canyon in Peru. Canyons are important geological features that provide habitats for various plants and animals. They also offer recreational opportunities such as hiking, rafting, and photography. The unique landscapes of canyons attract tourists and researchers interested in studying their natural history and ecology.