The Annamite Mountain Range extends for 2,130 km and separates the country to Vietnam on the east. It also serves as a physical barrier between the Chinese-influenced culture of Vietnam and the Indianized states of Laos and Thailand. The mountain range is sparsely inhabited by tribunal minorities who traditionally have not acknowledged the border with Vietnam. Thus the contact between the Vietnamese and Laotians side has been confined to trading.
The country is bounded by mountainous 423 km border with China and share 235 km Mekong River border with Burma and 541 km shorts southern border with Cambodia and Khmer ruins at Wat Po and other southern location attest to the long history of connection between the Lao and the Khmer people.
Laos is primarily consisted of mountains and has an elevation above 500 meters with steep terrain, narrow river valleys and low agricultural lands. Khammouane Plateau in the center and the Bolaven Plateau in the south bring variety to the mountainous landscape. Situated in Xiang province is Phou Bia the highest mountain in the country with 2,817 m. The southern “panhandle” of the country comprises large level areas in Savannakhet and Champasak provinces that are appropriate for extensive paddy rice cultivation and livestock raising. About 20% of the land area is covered by the alluvial plains and the terraces of the Mekong and its tributaries.
Most of the rivers and streams in Laos eventually end up feeding into Mekong through one of its 15 tributaries making a total of 2,400 km of waterways and feeding the Mekong with more than half of its overall water flow. Mekong River is the lowest point of the country with 70 m deep. During the dry season its low-water phase become dry but do rises more than 6 m during the monsoon period. Mekong River can be described as wide with numerous rapids in navigable stretch between Vientiane and Savannakhet. In the extreme southern part of the country and below Savannakhet are large rapids and waterfalls. These areas are prone to floods during rainy season.
The western border of Laos is demarcated by Mekong River, which is more than 1.805 kilometers – almost half of the entire length passes through the country thus it serves as a significant artery for transportation. Mekong River serves as a facilitator for communication between Laos and northeast Thai society.
About two-thirds of the country is forested, however the growing population, the plan for additional hydroelectric facilities and commercial exploitation have brought a new and increasing pressures and threats regarding environmental degradation. Government intervention has been necessary to limit the clearing of forests and resettlement of population to lowlands locations has been encouraged for rice paddy cultivation.