A large body of water surrounded by land is called a lake. Lakes are significant features on Earth, forming in various ways including tectonic activity, glacial movements, or volcanic craters. They can vary greatly in size, depth, and ecological significance, hosting a diverse array of flora and fauna. Lakes are vital for local ecosystems and provide resources like drinking water, recreation, and habitat for numerous species. Some famous lakes include the Great Lakes in North America and Lake Baikal in Siberia, which is known for being the deepest lake in the world.