Colombia has both torrid jungles and majestic, snowcapped mountains. By far the most prominent physical features are the three great Andean chains that fan north from Ecuador. The Andean interior is the heart of the country, where in pre-Columbian days the highly advanced Chibcha lived. It has the largest concentration of population and is the area of large-scale cultivation of coffee, Colombia's major crop.
Of the three principal Andean ranges, the Western Cordillera is of the least economic importance. One of Colombia's major cities, Cali, lies just east of the range, in the upper Cauca valley. The Central Cordillera has a towering chain of volcanoes (e.g., Tolima) and is the divide between the valleys of the Magdalena and the Cauca rivers. It was until the 19th cent. an undeveloped region, but with improved transportation, the introduction of coffee culture, and the exploitation of high-grade coal reserves, its cities of Medellín and Manizales have become the economic and industrial core of the republic. A third major city in the Central Cordillera is Armenia. The Eastern Cordillera is the longest chain. Its western slopes yield coffee, and in its intermontane basins grains and cattle are raised. The area is rich in iron, coal, and emeralds. Among the leading cities of the highland basins are Tunja, Bucaramanga, and Cúcuta, in addition to Bogotá. In the eastern foothills of the Andes some hundred miles east of the capital lies a vast supply of light crude oil. Discovered in 1992, the oil fields constitute the largest find in the Americas since Alaska's Prudhoe Bay field (1969) and have revitalized Colombia's petroleum industry.
To the east of the Andes lies more than half of Colombia's territory, a vast largely undeveloped lowland. The plains are crossed by navigable rivers, tributaries of the Orinoco and Amazon systems. The northern section consists of savannas (the llanos), which are devoted to a large extent to cattle and sheep grazing. Villavicencio, at the region's western end, is its major urban center. The dense jungles of the extreme southeast are of negligible economic importance. Leticia is the country's southernmost town, and its only port on the Amazon River. A fourth mountain chain, the Cordillera del Chocó, runs parallel to the Pacific N of Buenaventura. The range's slopes yield dyewoods and hardwoods, rubber, tagua nuts (vegetable ivory) and other forest products, and gold and platinum.
On the Pacific are the ports of Buenaventura and Tumaco, terminus of a pipeline from the oil-rich area of Putumayo across the mountains. Colombia's chief ocean ports, however, lie on the Caribbean coast to the north: Santa Marta, Cartagena, and Barranquilla. At Mamonal, adjacent to Cartagena, is the terminus of the pipeline from the Barrancabermeja oil fields. In the north, separating the La Guajira peninsula from the rest of the country, is the magnificent Sierra Nevada de Santa Marta, which contains Colombia's highest peak, Pico Cristóbal (18,947 ft/5,775 m). The difficult terrain in Colombia limits the availability of road and rail transportation and makes air and water travel especially important.