Introducing Amazon Basin
As you head southeast from the Andes, dry scrubland grows more lush, turning into almost impenetrable jungle long before you ever reach the Amazon. This huge, wild region, which Colombians call Amazonia, accounts for a third of the country's total area - it's about the size of California and larger than Germany. Biologists will probably never finish cataloging the region's dizzying array of flora and fauna. Likewise, visitors can never quite account for the strange exhilaration they feel when they come face-to-face with the rainforest for the first time.
With transportation largely limited to the rivers that crisscross the jungle, indigenous peoples have in many cases been able to preserve their cultures more or less intact. The region remains an ethnic and linguistic mosaic, with more than 50 languages (not counting dialects) belonging to some 10 linguistic families.
Unfortunately, isolation has made Amazonia a hotbed for cultivation of the coca plant, and the processing of its leaves into cocaine. It's an ideal base for leftist rebels. In many areas of the Caquete and Putumayo departments, they run what amounts to a state within a state supported by proceeds from the region's drug trade. These regions are off-limits to outsiders.
Fortunately, you can safely visit the Amazon itself by flying directly to Leticia, a town that sits on the banks of the great river - and is right at the borders with Brazil and Peru. It occupies a quirky strip of land that penetrates the territories of the other two countries, and that in fact was not part of Colombia until the three nations signed a treaty in 1922. From here you can venture up and down the river or strike out into the surrounding rainforest.