Antarctica is the world's largest desert by area, covering the Antarctic continent and its ice sheet.
Deserts are defined by very low precipitation, not by heat or sand. Antarctica receives little precipitation because extremely cold air holds little moisture; much of the interior gets less than 50 millimetres of precipitation annually. Its surface is dominated by ice, but it still meets the geographic definition of a desert.
The Sahara is the world's largest hot desert, while Antarctica is the largest desert of any type. Antarctica covers about 14 million square kilometres, making it larger than Europe and Australia. Almost all of its water is frozen in the continental ice sheet, which contains most of Earth's freshwater ice.
The Antarctic Ice Sheet also makes Antarctica the highest continent on average. Its extreme cold, dryness, powerful katabatic winds, and seasonal darkness create one of Earth's most severe environments.