What is the largest cold desert in the world?

Which desert is known for its unique 'fairy circles'? In which country is the Arabian Desert primarily located? What is the largest hot desert in the world? Which desert is located in the southwestern United States and northwestern Mexico? Which desert is the largest continuous sand desert in the world? In which continent is the Patagonia Desert located? What is the name of the desert that covers parts of Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, and… What is the name of the desert that covers about 270,000 square kilometers in Western Australia?