The Colombian Massif (from the Spanish Macizo Colombiano), also known colloquially as Nudo de Almaguer, refers to a group of mountains within the Andes of south central Colombia.

To the south is the Pasto Massif and to the north begins the Central and Eastern Andes.

[1] This area is identified as the source of 70% of the Colombian freshwater for human consumption and irrigation.

The massif contains 362 high mountain bodies of water, 13 páramos and other ecosystems rich in flora and fauna.

Very few people have traversed the mountains of this region because it is covered by rugged terrain and an impenetrable and cold páramo environment, both of which are natural guardians which preserve the water sources that provide water for half of Colombia before emptying into the sea.