Say Amazon and most of us probably think of the on-line shopping monster, then maybe of the South American river or one of the planet’s last great pristine wildernesses, inhabited a few “primitive” indigenous tribes. However, despite the legends of El Dorado, I bet few of us really think of it as the home of ancient and long-lost civilisations. But then most of us aren’t archeologists equipped with modern technology.
Although until recently material evidence has been scarce it’s now thought that what we think of as primordial dense forest and jungle was in fact covered by a large network of settlements, lived in by large numbers of people with deep knowledge of earthmoving, river management, and plant and animal ecology, who were able to manage and alter their surroundings to create complex domesticated landscapes with gardens, forest-orchards and fisheries all run sustainably…
You’ve probably heard of Lidar – the acronym for Light Detection and Ranging – It works like radar, calculating distance by measuring the time it takes for a reflected signal to return. But while radar uses radio waves for its signal, lidar uses a pulse of light. Luckily you don’t need to know much about how its works just what it’s now capable of doing, and allowing humans to do.
Lidar systems on aircraft can fly over and scan vast tracts land or water using those pulses of light to create a 3D map of the terrain below, no matter how impenetrable or inaccessible in a fraction of the time it would take to survey from the ground. It makes Lidar a really powerful and essential tool in geology, oceanography, and perhaps surprisingly archaeology. It can “see” structures hidden below trees or other vegetation and so detect not only changes in ground level but buildings, the remains of roads, agricultural terraces, aqueducts, caves, and even things such as fences, ditches, earth banks and other boundaries.
Historic England have produced a really good guide to the use of Lidar in archaeology which is available free on their website.
A geoglyph – geometric earthwork around a settlement – and associated roads in Acre state, Brazilement
It has transformed archaeological research in many areas and in particular our understanding of Central and South America before the arrival of European invaders in the 16thc. While the cities of the Aztecs, Maya and other Meso-American civilisations have long been known about, its always been thought that in Amazonia, there wasn’t much by way of permanent settlements or infrastructure, even though indigenous societies have lived there for thousands of years. It was also long thought that the soil was generally too poor to support any intensive agriculture.
Amazonia, with the locations of the sites mentioned later in the post
Now, thanks to Lidar, that’s all changing. Amazonia is vast almost beyond comprehension, and of course it’s not uniform. Apart from the tropical rain forest and the floodplains of the Amazon and its 1100 major tributaries, there are mountainous regions on all sides, areas with monsoon-like climates and others with Savannah grasslands. Settlement pattern obviously differ enormously but they tend to show forms of low density urbanism across every social and linguistic group, all of whom developed sustainable agricultural systems as well as participating in hunting, fishing and gathering activities.
But of course there was archaeology before Lidar. One example of this is the work being done by Professor Michael Heckenberger, an anthropologist from the University of Florida, who has been working on and around the ancient site of Kuhikugu on Brazil’s Upper Xingu River for about 30 years alongside alongside the local Kuikuro people, who are the likely descendants of the original inhabitants.
A modern Kuikuro villages , with houses centred around a circular plaza follow the layout seen in a lidar image of the ancient town of Nokugu, settled from 640 to 1770 C.E. Yellow lines mark plazas and roads; blue lines indicate what were once defensive trenches with wooden walls.
He has discovered an intricate network of at least 15 what he describes as “low-density garden cities”, dating from at least 1,500 years ago, and with a total population in the tens of thousands. It was an urban society in many ways although not in the usual European sense, instead it is distinctly Amazonian. So why didnt we know about them? Simply because there are no stone buildings. Instead these settlements were built using only materials such as packed earth, timber and thatch available from the surrounding rainforest. As result sites are rapidly reclaimed by the jungle if and when people leave. Because there’s nothing like the ruins Europeans expected to see from lost civilisations it was assumed there was nothing significant to be seen and never had been.
Heckenberger found houses and gardens, straight broad roads, causeways and bridges, central plazas with defensive palisades and ditches surrounding it, as well as ponds, wells, orchards, and fields of crops. The inhabitants also managed hundreds of tree species, some of which show evidence of domestication and effected long-lasting changes in forest composition. In other words Amazonia had as complex a civilisation as any other in the world at the time of Columbus’s arrival in 1492
Since then the Brazilian National Institute for Space Research has used Lidar to survey swathes of the Amazon basin – over 5000 km2 so far – with revelatory results. Initial analysis of the images revealed traces of a lost world with statistical modelling suggesting that somewhere between 10,000 and 24,000 pre-Columbian “earthworks” exist across the Amazon River basin, largely hidden by the rainforest. Until then less than a thousand had been known, mostly discovered through deforestation, rather than traditional archaeology and very few of them are in areas with any form of environmental protection. Archaeologists working from the latest Lidar data from a different area reported in Nature in July 2026 now think that the numbers of earthwork settlements is perhaps as many as 30,000 supporting a population of 6-10 million people.
Elsewhere, particularly on the western side of Amazonia in the Bolivia and Ecuador and other major urban centres are rapidly being discovered. In 2022 archaeologists from Bonn University working in the south-west Bolivian Amazon announced the discoveries they had made in the Llanos de Mojos area. There were as many as 26 sites thought to be up to 1400 years old, including two large urban centres, belonging to the Casarabe culture, c.AD 500–1400. Cotoca covers about 147 hectares and Landívar about 315 hectares. Both are surrounded by successive rings of moat and rampart fortifications. They had extensive artificial terracing and raised fields, huge earthen-platform buildings and conical pyramids over 70 feet tall as well reservoirs, canals and straight causeways and tracks radiating into the surrounding countryside.
When Heckenberger saw these initial reports from Bolivia he was clear: “This is in my mind the clearest case of a fully urbanized Amazonian landscape… It’s a marvellous piece of work. It shows really remarkable range of things that humans did in the past to work with their landscapes and work with larger and larger populations.”
Further north in Ecuador the Upano Valley. is another area full of earth mounds and terraces. It had been explored conventionally over 50 years ago, establishing that a civilisation had inhabited the valley approximately 3,000–2,000 years ago, probably because of the rich volcanic topsoil that was good for agriculture.
More recent work by French archaeologist Stéphen Rostain who has worked in Amazonia for several decades led to the publication in 2013 of Islands in the Amazonian Forest: Landscape Management in Pre-Columbian Amazonia.”
Then in 2022 along came Lidar. which led to the uncovering of the vestiges of a 1500-3,000-year-old gardened metropolis with more than 6,000 earthen platforms laid out in a geometric pattern and connected by public “squares”. A complex network of roads and paths connected 15 separate urban centres, all surrounded by tropical rainforest and which may have had a population in the tens of thousands. Such extensive early development is comparable to similar Mayan urban systems in Mexico and Guatemala.
For more the Upano Valley research see “Two thousand years of garden urbanism in the Upper Amazon”, in Science, 11th January 201. It’s free to access but you have to open an account
Right: Terra Preta and Left: “normal soil”
The Upano Valley was lucky in having rich soil so how did settlements elsewhere in Amazonia where the soil was much poorer manage? It turns out they had mastered the idea of composting long before the rest of us. There are mysterious patches of what is known as terra preta, or “dark earth”. A 2024 survey across 26,000 km² of one region concluded that dark earth probably occupies at least 3–4% of the land. These areas which can be up to 12 feet deep were clearly created by humans who systematically composted organic waste creating a fertile rich soil. This is in stark contrast to most Amazon soil, that is naturally acidic and rich in minerals that are toxic to plants at high concentrations.
But it’s not just organic matter such as vegetation, food scraps, manure, and urine because mixed in with it are inorganic material including ash, pottery, bone and shells. The oldest levels have been dated to around 5000 years ago, with a peak around 2000 years ago and then a sudden halt around 500 years ago, which coincides of of course with the arrival of the conquistadores. Similar systems seem to have developed elsewhere across Amazonia and modern agriculture simply cannot reproduce the fertility of the original soil in the long term, as many collapsed attempts have demonstrated. These ancient indigenous methods are seen to be so effective that several contemporary bio-economy companies have begun manufacturing similar dark soils – now known as biochar from the partially burnt wood, charcoal and ash it contains – to enhance fertility and store carbon.
For more on that see The ‘dark earth’ revealing the Amazon’s secrets, by Zaria Gorvett, 2024, and Ancient Amazonians intentionally created fertile “dark earth” by Jennifer Chu,2023
I said earlier that these settlements were not known about by Europeans. That’s not quite true because in fact they were still in existence when the Spanish conquistadors arrived and they were known to, and reported by, a group of early Spanish explorers. Father Gaspar de Carvajal was a member of an expedition that crossed from Peru into Amazonia in the early 1540s and he kept a diary. Descubrimiento del rio de las Amazonas (“Discovery of the Amazon River”). I’ve just picked out a few phrases to make the point about the number of settlements and density of population but you can read much more from it in the AI translation of the original Spanish which I’ve uploaded here] .The Werner Herzog film Aguirre, the Wrath of God was loosely based on Carvajal’s account.
The expedition building their own boats from Theodore de Bry’s collections of travel accounts Grandes Voyages or America, 1594
Having crossed the Andes the party of about 60 built their own boats – known as brigantines – and then set off. Although there are large stretches of their journey particularly at the start where there were no visible signs of habitation, further on there were densely populated areas. In one section “no village was more than a crossbow shot away from the other (…) and there was a village that stretched for five leagues without interruption from house to house, which was a marvellous thing to see. Because we were merely passing through — or rather fleeing — we had no opportunity to discover what lay farther inland.But judging by the appearance and disposition of the country, it must be the most densely populated land that has ever been seen.”
“The farther we travelled, the more densely inhabited and the better we found the country to be….There were days on which we passed more than twenty settlements, and that was only on the side along which we ourselves were travelling, because the river was so broad that we could not see the opposite bank…Moreover, two leagues or more inland, and sometimes at a shorter distance, very large towns could be seen gleaming white.
The material culture was rich too: gold and silver ornaments, festival costumes and pottery which “was the finest that has ever been seen in the world… all of it was glazed and enamelled in many colours, so vivid as to cause astonishment.” He reports too on the turtle and fish farms, on areas where fruit trees had been planted or where herbs grew
Carvajal’s accounts was dismissed by later historians as fabrications because there was no real sign of such cities – ie no ruins – and in any case the acidic soils of Amazonia were thought incapable of supporting the level of agriculture necessary to sustain such a society. And he did include some dubious passages especially about encountering female warriors who were of course the Amazons [you can read more about them in the AI translation of the original Spanish which I’ve uploaded here]
So what happened to all these Amazonian “garden cities”? Carvajal may well have been part of the problem. His expedition almost certainly took diseases unknown to the Amazonians and in any case as Mac Margolis pointed out in The Guardian last year: “waves of colonial occupiers, bearing guns, pathogens and the Bible, made short work of these ancient Amazonians, whose populations soon collapsed and with them, their towns.” This was doubly depressing because not only did the civilisations effectively vanish but their disappearance led to the until now standard view of the indigenous people. ie that they lived small, isolated groups, and were uncivilised, and therefore unimportant. Even today such views hold sway in many minds especially corporate and political.
Many of the sites that were discovered in land clearance for agriculture have been or are under threat and even giving them legal protection has little effect. However it’s clear that attitudes are beginning to change. One of the other positive outcomes of Lidar has been the project for Mapping the Archaeological Pre-Columbian Heritage of South America (MAPHSA) which began in 2023. It. plans to produce the first integrated database of the pre-Columbian archaeological heritage of South America that will be open access and serve as the primary resource for heritage protection and research repository for the continent. So far over 23,000 sites across Brazil and Colombia have been added although the database isn’t yet publicly accessible.
Archeologists at work on one of the newly discovered settlements
Though it faced virtual extinction the culture that thrived in Amazonia adds to the growing evidence that the Amazon isn’t actually one of the world’s great untouched wilderness areas— but one that was carefully managed by its inhabitants until the arrival of Europeans stopped that. The archaeology now taking place shows these lost rainforest towns are remarkable for what they tell us about the way the inhabitants lived off the land and in harmony with it. As these pre-colonial landscape and ancient practices are being uncovered they show the extraordinary achievements that were made: a legacy that is still observable in the soil, and the composition and biodiversity of the contemporary tropical forest That has many implications for contemporary environmental management if only we’d learn from them!
.svg){kind=link}
You must be logged in to post a comment.