The Andes mountains form the most populated region of Colombia and contain the majority of the country's urban centres. They were also the location of the most significant pre-Columbian indigenous settlement. 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 Cordillera Occidental runs adjacent to the Pacific coast and includes the city of Cali; the Cordillera Central runs up the centre 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; and the Cordillera Oriental extends north-east towards the Guajira Peninsula, and includes Bogotá, Bucaramanga and Cúcuta.