The Amazon's lost civilisation: Hidden network of 20,000 structures reveals rainforest once teemed with MILLIONS of people

The Amazon rainforest may look like one of the last truly wild places on Earth – but experts have discovered evidence of a sprawling lost civilisation hidden beneath its dense canopy.Scientists say the untamed wilderness was once home to millions of people who ‘flourished’ in sprawling communities connected by roads and ceremonial centres.Using laser technology to peer through the rainforest, researchers uncovered hundreds of previously unknown ceremonial structures hidden beneath the trees.The findings suggest the ancient Aquiry civilisation occupied an area the size of the UK and may have built more than 20,000 earthworks across the region.Researchers estimate that between 1.25 million and three million people lived there at the start of the first millennium, overturning long-held beliefs about the Amazon's past.The huge settlements featured political and religious centres linked by an extensive network of roads, revealing a remarkably sophisticated society.The team, from the University of Helsinki, said the discovery could transform our knowledge of how ancient people lived in one of the world's most challenging environments.‘Our findings overturn our understanding of the Amazon region’s past,’ Professor Martti Pärssinen, lead author of the study, said. A geoglyph built by the Aquiry civilisation in Acre, Brazil. This large design was made by digging and shaping soil Lidar uses infrared light to uncover the shapes hidden underneath dense tree canopies. The huge settlements featured political and religious centres linked by an extensive network of roads, revealing a remarkably sophisticated societyFor the study, the team used an airborne laser scanning technique known as LiDAR, which fires millions of laser pulses through gaps in the forest canopy to produce a detailed map of the ground hidden beneath the trees.The scans revealed nearly 400 previously unknown earthworks – giant structures created by digging and shaping soil into enormous ditches, banks and geometric enclosures.The researchers then used computer modelling to estimate how many similar sites are likely to remain undiscovered, concluding there could be around 20,000 earthworks spread across an area of roughly 400,000 square kilometres.Many of the structures were built by digging deep ditches and piling the excavated earth into raised embankments, creating enormous shapes including circles, squares, rectangles and octagons, with some measuring hundreds of metres across.Rather than serving as forts or homes, many of these earthworks appear to have been ceremonial and political centres, where people gathered for rituals, trade, feasting and important community events.According to native oral traditions, these centres were built to foster relations among communities.They also served as venues for gatherings, political decision-making and displays of chiefly generosity. Ceremonies included ritual dance, music, feasting, athletic contests and ball games.The largest sites were linked by remarkably straight roads and causeways, suggesting the settlements formed part of a carefully planned regional network rather than isolated villages scattered through the rainforest. The scans revealed nearly 400 previously unknown earthworks – giant structures created by digging and shaping soil into enormous ditches, banks and geometric enclosures The green points on this map indicate the areas where the huge earthworks were picked up by scanners The Aquiry civilisation An ancient Amazonian civilisation that lived in what is now the Brazilian state of AcreThey flourished during the first millennium AD, with researchers estimating their population peaked between AD 100 and 300 Scientists estimate the region was home to between 1.25 million and three million people, making it one of the largest known pre-Columbian populations in the Amazon Their territory covered around 400,000 square kilometres (154,000 square miles) in the southwestern Amazon—an area roughly comparable to the size of the UK They constructed thousands of giant earthworks - huge ditches and raised embankments forming circles, squares, rectangles and octagons - along with roads connecting major ceremonial centresThe Aquiry cultivated crops including maize, cassava and squash, practised horticulture and managed valuable tree species while maintaining much of the surrounding rainforest The findings indicate the Aquiry people transformed the landscape on a vast scale while still maintaining extensive areas of forest.This challenges the long-held belief that the Amazon was an untouched wilderness before European contact.The researchers explained that the Aquiry burned sections of forest to clear land for the ceremonial centres and for fields of maize, squash and cassava.This civilisation also practised horticulture and managed valuable tree species, they said.‘The research shows that the human impact on the Amazon’s environment has been far greater than previously believed,’ Professor Pärssinen added.‘This has direct implications for our understanding of the region’s biocultural history.’He explained the Aquiry were not a single realm but a network of many different communities.It is not known what languages were spoken across these communities, nor what they called themselves. It is also not clear what caused the civilisation's apparently rapid collapse around 850 AD.Researchers say only a tiny proportion of the rainforest has so far been surveyed using LiDAR.This means thousands more ancient settlements and monumental earthworks could still lie hidden beneath the jungle canopy.‘On the basis of both existing data and our LiDAR documentation, we show that this cultural area alone contains as many earthworks as previously estimated for the whole of Amazonia,’ the researchers wrote in the journal Nature.‘We also propose that the total human population of the area in 100 - 300 AD was 1.25 to three million people.‘If similar results are found elsewhere in Amazonia, the total precolonial population density and its effect on the current Amazonian soil and forest structure, biodiversity and even some modelling of the global climate should be re-evaluated.’