The region is bounded by the East Andes along the western edge and extends to the Venezuelan and Brazilian borders in the east. The northern limit begins with the Guaviare and Vichada Rivers and extends south to the Putumayo and Amazon Rivers.
The Amazon region is divided up into distinct subregions:
Amazon foothills: bordering the East Andes
Caquetá River Plain: the main watershed of this region
Amazon Trapezium: the area of land that actually borders with the Amazon River
Other important rivers include the Vaupés, Apaporis and Yarí.
Biodiversity
The tropical rainforest, classified more specifically as a tropical moist broadleaf forest. Within the Colombian Amazon region, there are five moist forest ecoregions:
Caquetá moist forests: the largest part of the Colombian Amazon region centered on the Caquetá, Vaupés, Yarí, and Apaporis Rivers
Napo moist forests: the southwest corner of the Colombian Amazon region, which borders the Andes and includes the headwaters of the Caquetá and Putumayo Rivers