The Andes mountains form the Andean region of Colombia; one of six natural regions alongside the Caribbean, Pacific, Orinoco (lowlands), Insular (islands), and Amazon regions. Despite the complicated topography of the Andean region, it is the most populous area of Colombia, with the majority of major urban centers located within the region.
The Andean region of Colombia consists of a cordillera of three mountain ranges, which dissect the country from the Northern border with Venezuela, to the Southwestern border with Ecuador, where the Andes mountains continue their journey as the longest continuous mountain range in the world. The three mountain ranges are the West Andes (Cordillera Occidental), the Central Andes (Cordillera Central), and the East Andes (Cordillera Oriental). The Andean region also consists of a series of lowland valleys and rivers which intervene the mountains.