The largest desert on Earth is Antarctica. While many may think of deserts as hot, sandy environments, a desert is defined by its low precipitation levels. Antarctica is classified as a cold desert, receiving less than 2 inches (50 mm) of precipitation annually, mostly in the form of snow. Its vast ice sheets cover an area of about 14 million square kilometers (5.4 million square miles). The extreme cold and harsh conditions make it one of the most inhospitable places for life. Despite this, Antarctica is home to unique ecosystems adapted to its environment, including various species of birds and seals.