Mongolia Listen/mɒŋˈɡoʊliə/ is a landlocked country in East and Central Asia. It borders Russia to the north and the autonomous region of Inner Mongolia, China to the south, east and west. Ulan Bator, the capital and largest city, is home to about 45% of the population. Mongolia’s political system is a parliamentary republic. The area of what is now Mongolia has been ruled by various nomadic empires, including the Xiongnu, the Xianbei, the Rouran, the Gökturks and others.