Laosis a landlocked country in Southeast Asia and the thickly forested landscape consists mostly of rugged mountains, the highest of which is Phou Bia at 2,817m (9,242 ft), with some plains and plateaus. The Mekong River forms a large part of the western boundary with Thailand, whereas the mountains of the Annamite Chain form most of the eastern border with Vietnam.
The climate is tropical and monsoonal. There is a distinct rainy season from May to November, followed by a dry season from December to April. Local tradition holds that there are three seasons (rainy, cold and hot) as the latter two months of the climatologically defined dry season are noticeably hotter than the earlier four months. The capital and largest city of Laos is Vientiane, and other major cities include Luang Prabang, Savannakhet and Pakxe.
In 1993, the government set aside 21% of the nation's land area as National Biodiversity Conservation Areas (NBCA), which may be developed into a national park system.
Laosis the home to the Indochinese tiger, the giant gaur, and the Asian elephant. A number of animal species have been discovered or re-discovered in Laos in recent years. These include the striped or Annamite rabbit, the saola, and most recently the Laotian rock rat orkha-nyou.