Antarctica contains the largest desert on Earth, the Antarctic Desert.
A desert is defined by very low precipitation, not by high temperatures. Antarctica receives little snowfall across its vast interior, and the extremely cold air holds very little moisture. Ice and snow remain because melting is limited, so the continent is also the largest ice sheet region on Earth.
The Antarctic Desert covers the continent, including the high polar plateau and the ice-covered coastal areas. Some parts of the interior are called the McMurdo Dry Valleys, where strong winds and exceptionally dry conditions leave portions of the ground nearly ice-free.
A common mistake is to call the Sahara the world's largest desert. The Sahara is the largest hot desert, while Antarctica is larger overall. Antarctica is a continent surrounded by the Southern Ocean, not a country, and it has no permanent native population.