The section of the jungle is near the outskirts of the Colombian city of Leticia, close to the borders of Perú and Brazil.
It will include all the habitats that the Colombian rainforest dwellers need in order to survive and draw upon natural resources.
Over 500 species of birds, 150 types of mammals and thousands of fish live in the area.
By buying up this part of the forest, it will no longer be under threat from woodcutters, farmers and drug-traffickers harvesting coca leaves for later chemical manipulation.
These activities pose a very real threat to the survival of Amazonian inhabitants.
And in recent years, the expansion of the city of Leticia has become another danger to indigenous people in the heart of the Amazon.
The Spanish scientists behind the move form part of the charity Manguaré, which is dedicated to preserving the South American rainforest and has already bought 80 hectares of the jungle as a pilot project.
INDIGENOUS Amazonians have reached an agreement with Spanish scientists allowing the latter to buy 100,000 hectares of rainforest for conservation reasons.