Area

Topography
The principal physical feature of Bolivia is the Andes mountain range, which extends generally north to south across the western part of the country. On the west, near the border with Chile, is the Cordillera Occidental, or western range, and on the northeast is the Cordillera Real, the main range of the Andes. Bolivia is divided into three distinct regions: the altiplano, or plateau region; the yungas, a series of forested and well-watered valleys embracing the eastern mountain slopes and valleys; and the llanos, or the Amazon-Gran Chaco lowlands. The altiplano lies between the Cordillera Occidental and the Cordillera Central. The northern part contains, at its end, Lago Titicaca, the highest large navigable lake in the world.

The southern part of the plateau is arid as a desert with the most big salt lake's of the world, the Salar de Uyuni and Coipasa. Lying on the eastern slopes of the Andes are the yungas. Stretching east and northeast from the mountains are the great Amazonian llanos, containing large grassy tracts and, along the rivers, dense tropical forests. Much of this region becomes swampland during the wet season (December, January, and February); large areas, however, lie above the flood line and are rich grazing lands. In the southeast, separated from the Amazonian plains by the Chiquitos highlands, are the dry, semitropical plains of the Gran Chaco.

Major Rivers and Lakes
Four rivers comprise Bolivia's drainage system in the northern and northeastern valleys and plains: the Río Beni and its main affluent, the Río Madre de Dios; the Rio Guaporé, which forms part of the boundary with Brazil; and the Río Mamoré. In the southeast, the chief river is the Río Pilcomayo, which flows through the Gran Chaco region to feed the Río Paraguay, eventually draining into the Río de la Plata. The Desaguadero River, outlet for Lago Titicaca, feeds Lago Poopó to the southeast. Bolivia shares control of Lago Titicaca with its neighbor Peru.

Climate
Bolivia is situated entirely within the tropics, but because of its varied elevation it has a wide range of climate. In the higher elevations, the climate is cold and dry but generally healthful, in spite of the cutting winds, the thinness of the atmosphere, and the daily extremes of temperature. In the lower-lying regions, the climate is warmer. The mean annual temperatures range from about 8°C (about 46°F) in the Altiplano to about 26°C (about 79°F) in the eastern lowlands.