In the jungle-clad mountains of the Sierra Nevada, Colombian farmers process coca leaves in their cocaine lab. First, take some coca leaves, a number of nasty substances, add some bullets, some scary para-military soldiers, a dash of guerrillas, some corrupt cops, and a pinch of coca farmer, and you've got one of the world's deadliest drug cocktails. This is one of the reasons why this area of the world serves as the central hub for the world's dark economy.