Andean natural region
The Andes mountains form the most populated region of Colombia and contain the majority of the country's urban centers. They were also the location of the most significant pre-Columbian indigenous settlements. Beyond the Colombian Massif in the south-western departments of Cauca and Nariño, the Colombian Andes divide into three branches known as "cordilleras" (from the Spanish for "mountain range"): the West Andes run adjacent to the Pacific coast and is home to the city of Cali. The Central Andes run up the center of the country between the Cauca and Magdalena river valleys (to the west and east respectively) and includes the cities of Medellín, Manizales and Pereira. The East Andes extend northeast towards the Guajira Peninsula, and includes the cities of Bogotá, Bucaramanga and Cúcuta.
Antarctandes
Some geologists consider the Antarctandes a southernmost continuation of the Andes Range System on Antarctica. According to this theory the Andes start at the border between Colombia and Venezuela; run along western South America; submerge into the Atlantic Ocean to the east of Tierra del Fuego to form the underwater Scotia Arc mountain range; resurface periodically in the Shag Rocs, South Georgia and the South Sandwich Islands, South Orkney Islands and South Shetland Islands; and finally resurfacing on the northern Antarctic Peninsula. Chile calls the peninsula "Tierra de O'Higgins", and Argentina "Tierra de San Martín".