Lost cities of the Amazon Ancient garden metropolises uncovered by 3D mapping

For decades, archaeologists have believed that human occupation of the Amazon basin was far older, vaster and more urbanised than the textbooks suggested.

- Mac Margolis

But evidence was scant; artefacts were scattered, and there were too few people on the ground to fully assess the magnitude of what lay in the dense forest. Then they found a shortcut – lidar.

Lidar (light detection and ranging) uses pulses of light to create a 3D map of terrain in a fraction of the time it would take to survey from the ground. One of those making the most of the technology is Vinicius Peripato, an analyst with the Brazilian National Institute for Space Research. By combining lidar datasets, he and his team are discovering traces of a lost world: evidence that between 10,000 and 24,000 pre-Columbian "earthworks" exist across the Amazon river basin.

While the remote scans still need to be verified on-site, Peripato says the findings so far make a compelling case that ancestral Amazonians systematically built up large urban centres and engineered their habitat to their needs and appetites, with composted gardens, fisheries, and forests groomed into orchards, in complex, sustainably run systems – which could offer lessons for modern cities.

The discovery challenges historical ideas of a pristine jungle too harsh to sustain human occupation. "It's really incredible. Our research ended up guiding the course of several others, and not just in archaeology," says Peripato. "Ecologists have been trying to understand the differences between forests that have been domesticated and virgin forests. I'm a geographer, and over time I've had to delve into archaeology and historical ecology to understand this pre-Columbian dynamic."

By the time Old World caravels (small Spanish or Portuguese sailing ships) dropped anchor off what would come to be known as South America, the habitat that Europeans had imagined to be a green blank page was in fact a hive of urban life. But waves of colonial occupiers, bearing guns, pathogens and the Bible, made short work of these ancient Amazonians, whose numbers and towns soon collapsed.