Mongolia is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of 1,564,116 square kilometres, with a population of just 3.3 million. Mongolia is the world's largest landlocked country that does not border a closed sea, and much of its area is covered by grassy steppe, with mountains to the north and west and the Gobi Desert to the south.
The name 'Gobi' is a Mongol term for a desert steppe, which usually refers to a category of arid rangeland with insufficient vegetation to support marmots but with enough to support camels. Mongols distinguish Gobi from desert proper, although the distinction is not always apparent to outsiders unfamiliar with the Mongolian landscape.
Gobi rangelands are fragile and easily destroyed by overgrazing, which results in expansion of the true desert, a stony waste where not even Bactrian camels can survive. The arid conditions in the Gobi are attributed to the rain shadow effect caused by the Himalayas. Before the Himalayas were formed by the collision of the Indo-Australian plate with the Eurasian plate 10 million years ago, Mongolia was a flourishing habitat for major fauna but still somewhat arid and cold due to distance from sources of evaporation. Sea turtle and mollusk fossils have been found in the Gobi, apart from well-known dinosaur fossils. Tadpole shrimps are still found in the Gobi today. The eastern part of Mongolia including the Onon and Kherlen rivers and Lake Buir form part of the Amur river basin draining to the Pacific Ocean. It hosts some unique species like the Eastern brook lamprey, Daurian crayfish and Daurian pearl oyster in the Onon/Kherlen rivers as well as Siberian prawn in Lake Buir.
Mongolia had a 2019 Forest Landscape Integrity Index mean score of 9.36/10, ranking it sixth globally out of 172 countries.