Exploring the Amazon rainforest sounds like an impossible task. It is an impenetrable, unforgiving place. Countless explorers have disappeared in its depths, snatched by disease, starvation, animals, or hostile locals. Even now, when we know so much about the Amazon, it retains a certain aura. We know that the Amazon basin produces more than 20% of the world’s oxygen; we know that it holds around one fifth of the world’s freshwater; we know that about half of the world’s species of animal, plant and insect live in the Amazon. And yet, we don’t know anything for certain. It is too big, too impressive, and too important for us to think we have conquered it.