We used to think the Amazon rainforest was virtually untouched, but it now seems to have been filled with sprawling settlements whose inhabitants shaped the land

Robert Harding Picture Library/National Geographic Image Collection

THE Amazon rainforest is so vast that it boggles the imagination. A person could enter at its eastern edge, walk 3000 kilometres directly west and still not come out from under the vast canopy.

This haven for about 10 per cent of the world’s species has long been regarded as wild and pristine, barely touched by humanity, offering a glimpse of the world as it was before humans spread to every continent and made a mess of things. It is painted in sharp contrast to the logged forests of Europe and the US.

But it now seems this idea is completely wrong. Far from being untouched, we are coming to realise that the landscape and ecosystem of the Amazon has been shaped by humanity for thousands of years. Long before the arrival of Europeans in the Americas, the Amazon was inhabited, and not just by a handful of isolated tribes. A society of millions of people lived there, building vast earthworks and cultivating multitudes of plants and fish.

We don’t fully understand why this flourishing society disappeared centuries ago, but their way of life could give us crucial clues to how humans and the rainforest could coexist and thrive together – even as Brazil’s new government threatens to destroy it.

Some of the first Europeans to explore the Amazon in the 1500s reported cities, roads and cultivated fields. The Dominican friar Gaspar de Carvajal chronicled an expedition in the early 1540s, in which he claimed to have seen sprawling towns and large monuments. But later visitors found no such thing.

The mysteries and rumours …