Colombia is located in the northwestern region of South America bordering to the east with Venezuela and Brazil; to the south with Ecuador and Peru; to the North with the Atlantic Ocean, through the Caribbean Sea; and to the west with Panama and the Pacific Ocean. Colombia is the 26th largest nation in the world and the fourth-largest country in South America after Brazil, Argentina, and Peru.
Despite its large territory, Colombia's population is not evenly distributed with most Colombians living in the mountainous western portion of the country as well as the northern coastline, most living in or near the capital city of Bogota. The southern and eastern portions of the country are mostly sparsely inhabited tropical rainforest and inland tropical plains containing small farming communities and indigenous tribes.
Colombia usually classifies its geography into five regions. Despite this The World Factbook makes no difference between Amazon region of Colombia (predominantly jungle) and the Orinoquia region of Colombia (predominantly plains).
The World Factbook considers most appropriate to divide the country into four geographic regions: the Andean highlands, consisting of the three Andean ranges and intervening valley lowlands; the Caribbean lowlands coastal region; the Pacific lowlands coastal region, separated from the Caribbean lowlands by swamps at the base of the Isthmus of Panama; and eastern Colombia, the great plain that lies to the east of the Andes Mountains.
The chief western mountain range, the Cordillera Occidental, is a moderately high range with peaks reaching up to about 13,000 ft (4,000 m). The Cauca River Valley, an important agricultural region with several large cities on its borders, separates the Cordillera Occidental from the massive Cordillera Central. Several snow-clad volcanoes in the Cordillera Central have summits that rise above 17,000 ft (5,000 m).
The valley of the slow-flowing and muddy Magdalena River, a major transportation artery, separates the Cordillera Central from the main eastern range, the Cordillera Oriental. The peaks of the Cordillera Oriental are moderately high. This range differs from Colombia's other mountain ranges in that it contains several large basins. In the east, the sparsely populated, flat to gently rolling eastern lowlands called llanos cover almost 60 percent of the country's total land area.
This cross section of the republic does not include two of Colombia's regions: the Caribbean coastal lowlands and the Sierra Nevada de Santa Marta, both in the northern part of the country. The lowlands in the west are mostly swampy; the reed-filled marshes of the area are called ciénagas by the people of Colombia.
The Guajira Peninsula in the east is semiarid. The Sierra Nevada de Santa Marta is a spectacular triangular snowcapped block of rock that towers over the eastern part of this lowland.