Colombia lies at the north-west corner of South America, sharing frontiers with Panama, Venezuela, Brazil, Peru and Ecuador. It has a surface are of 440,000 square miles, the fourth largest in the continent after Brazil, Argentina and Peru. It has 1,800 miles of coast, 1,000 on the Caribbean and 800 on the Pacific. There are also the islands, the most important being the San Andres and Providencia archipelago, some 450 miles away, the Islas del Rosario and San Bernardo, also in the Caribbean; and Gorgona, Gorgonilla and Malpelo in the Pacific. Territorial waters around the coasts and islands give Colombia some more distant neighbours, such as Costa Rica, Nicaragua, Honduras, Jamaica, Dominican Republic and Haiti.
The Andes Mountains split into the Central and Western ranges just inside the southern border of the country, and a little further up there is a further split to the Easter Range. The country is thus naturally divided into large regions: The Andes region contains most of the population, with major cities such as Bogotá, Medellín, Cali, Popayán, Pasto, Tunja, Manizales, Pereira, Armenia, Cúcuta, Bucaramanga, Neiva and Ibagué. The Caribbean region, with coastal plains stretching far inland, with cities such as Cartagena, Santa Matrta, Barranquilla, Riohacha, Valledupar, Sincelejo and Monteria - and the islands of San Andrés and Providencia, San Bernardo and other islands and cays.
The Pacific region, with a wild coast lines with jungles and mangroves, with Quibdo, the ports of Buenaventura and Tumaco and the islands of Gorgona , Gorgonilla and Malpelo. Orinoquia to the East, centred on Villavicencio; and the jungle region of Amazonia, with the river-port of Leticia, capital of the Department of Amazonas. There are other mountain massifs such as the Sierra Nevada de Santa Marta on the Caribbean coast, with among the highest peaks in the country, Cristobal Colon and Simon Bolivar, some 19,000 ft. high; La Macarena in the Department of Meta to the east and the Baudó range of hills running parallel to the Pacific coast. Colombia is rich in water, its many rivers offering great potential for power generation, transport and recreation.
The Magdalena, which rises in a tiny lake of the same name in southern Huila, is the main river in the system, flowing nearly 1,000 miles between the Central and Eastern ranges of the Andes to the Caribbean, at Bocas de Ceniza near Barranquilla. The Cauca runs between the Central and Western ranges, rising in the Sotara paramo in Cauca and flowing 650 miles up into the Magdalena. The Amazon is the border with Brazil and Peru over a stretch of 70 miles, at some points 1-1/2 miles wide. The Orinoco is the border with Venezuela for 150 miles. Other rivers, great and small, flow down from the mountains, forming a vast network which irrigates the valleys and the plains.