Laos is a landlocked country in Southeast Asia, lying mostly between latitudes 14° and 23°N (a small area is south of 14°), and longitudes 100° and 108°E. Its thickly forested landscape consists mostly of rugged mountains, the highest of which is Phou Bia at 2,818 metres (9,245 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 Range form most of the eastern border with Vietnam and the Luang Prabang Range the northwestern border with the Thai highlands. There are two plateaux, the Xiangkhoang in the north and the Bolaven Plateau at the southern end. The climate is tropical and influenced by the monsoon pattern. (Source Wikipedia).
Lao has 17 provinces : Attapeu, Bokeo, Bolikhamsai, Champasak, Hua Phan, Khammouane, Luang Namtha, Luang Phrabang, Oudomxay, Phongsali, Sayabouri, Salavan, Savannakhet, Sekong, Vientiane Capital, Vientiane and Xieng Khouang (including the special zone that might become the 18th province).