Mongolia is a landlocked country in the East Asia region. It is bordered by Russia to the north and China to the south, and covers an area of 1,564,116 square kilometers, making it the 18th-largest country in the world and the second largest landlocked country after Kazakhstan, as well as the largest landlocked country that does not border an inland sea. With a population of 3.5 million, Mongolia is the world's most sparsely populated sovereign state, excluding partially unrecognized Western Sahara. The country constitutes a significant portion of the Mongolian Plateau, and its natural environment is characterized by grassy steppe, mountains to the north and west, and the Gobi Desert to the south. Ulaanbaatar, the capital and largest city, is home to roughly half of the country's population.