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.
Llanos de Moxos
The Llanos de Moxos covers an area of in the lowlands of northern Bolivia, with small portions in neighboring Brazil and Peru. Most of the Llanos de Moxos lies within the departments of El Beni, Cochabamba, La Paz, Pando, and Santa Cruz. The Llanos de Moxos occupies the southwestern corner of the Amazon basin, and the region is crossed by numerous rivers that drain the eastern slope of the Andes Mountains. The low relief of the savannas, coupled with wet season rains and snowmelt from the Andes, cause up to half the land to flood seasonally.