Which desert was once a soggy swamp? Why is part of the Mojave Desert known as "Death Valley"? Which desert contains a very salty sea? The world has many deserts, some hot and sandy, others rocky, one even snowy and icy. Find out about these fascinating weather systems that have helped shape these landforms, the many different animals and plants that make their homes here, and how some people manage to survive in these inhospitable places.