The tropical rainforest shrouding northern Guatemala is a major part of the Maya’s mystique. At Tikal, pyramids puncture the tree canopy like mountain peaks through clouds, encouraging a sense of wonder that such a sprawling city could ever have been carved out of the jungle. This romantic setting invites visitors to imagine that they have stumbled across a mysterious lost civilisation, surrendered to nature. In reality, over six million people are still believed to speak at least one of the 24 surviving Mayan languages, while deciphering ancient carved stone glyphs has sketched the outlines of a regional history. As archaeological excavations at sites in the region continue to shed new light on Maya life, so too the true sophistication of these societies is emerging ever more clearly from the shadows of their rainforest home. Even so, recent survey has demonstrated with stunning clarity just how well the encroaching jungle has kept the Maya’s secrets.
In 2016, the PACUNAM Foundation in Guatemala funded an ambitious programme of aerial reconnaissance, which can stake a claim to being the most extensive use of LiDAR in support of archaeological investigation anywhere in the world. LiDAR, or ‘Light Detection And Ranging’, is a sophisticated prospecting tool, which uses aircraft-mounted lasers to strip away objects obscuring the ground surface to reveal subtle features barely visible to the human eye. Given the Maya presence, and the challenges that rainforests pose to traditional survey methods, it seemed certain that PACUNAM’s project would pay off, but even measured against these high hopes the results have been extraordinary. From a survey area of 2,144km2, split into ten blocks, over 60,000 new structures have been detected, including entire previously unknown settlements, as well as 105km of causeways and 59km of fortifications. Even at a well-known, and well-visited, site like Tikal, two new pyramids – previously thought to be natural features – were identified. In the years since receiving this data bonanza, archaeologists have been energetically testing what it all means.
In the jungle
The difficulty spotting on the ground some of the features documented by the LiDAR survey, even when their exact position is known, testifies to how effective the method is. ‘Things like roads, earthworks, and agricultural features are all elements that are very hard to pick out because they are long linear structures that run out of your field of vision,’ explains Tom Garrison, Assistant Professor in the Department of Anthropology at Ithaca College. ‘They are simply bigger features than you can make out in the jungle. In that sense, there is no way to equal the perspective that LiDAR provides. Since 2012, I have been directing a project examining a city called El Zotz, which is 22km from Tikal. I went out to look at a newly discovered causeway nearby, and took a very high-resolution GPS that contained all of the data. Even then, when I was standing on the causeway, it was a case of thinking, “Well, I guess I’m on it.” Once I had got myself grounded and looked around carefully, I could see that there was a very slight rise. But if I had been out there doing regular mapping methods, I never would have spotted it.’
‘We were confident that there would be something special in the LiDAR data, but nothing prepared us for the sheer density of Maya activity that showed up. Because of the scale of the survey, we’re not just looking at individual sites anymore: we’re looking at patterns across an entire landscape. One element of this is the causeways. We use this term to define roads within sites, say to allow ritual parades within a town by connecting different pyramid groups. But in some areas, you also have these really long causeways that link different sites. In some cases, they run right off the edge of our data, and we don’t even know what they’re connecting to. So there are definitely Maya superhighways out there!’
‘Another surprise came from the bajos. These are huge depressions in the geology of northern Guatemala; bajos means “low” in Spanish. They are basically nasty seasonal swamps, so when it’s raining they fill up, but we never thought that they were particularly productive for the Maya. There was some evidence that soil at the very edge of the bajos would be collected and used elsewhere, but we certainly didn’t expect there to be much in the middle of these things. On the LiDAR data, though, we can make out grids and networks of canals and what we think are field systems. Even when you go out and look at these anomalies on the ground, the features are so subtle that you couldn’t be sure they were real without the LiDAR demonstrating that these reticular patterns exist. We know from work in Belize that the Maya exploited wetlands there, so they must have found a way to use these swamp systems too. It fits really nicely, because when you see 60,000 new structures, one of the first questions you ask is “How did they feed all of these people?” So it’s really good to have that addressed too.’
Of course, the Maya period does not represent a single moment in time. Instead, the LiDAR data compresses thousands of years of culture into a single image of the landscape. Most of the new structures are believed to belong to what is known as the Classic period, which stretched from around AD 250-1000. As its name implies, this was the period when Maya society reached its zenith, so it seems a reasonable working model that this was also the time when they left the biggest footprint on their jungle home. Even so, the beginning of the Classic period used to be tied to major innovations, including the raising of glyphic inscriptions, but, as is so often the way, fresh archaeological discoveries have blurred such clear distinctions. One painted inscription, for example, has been radiocarbon dated to the 3rd century BC, suggesting literacy centuries before the Classic period. This is just one of many signs that the Preclassic period, running from c.2,000 BC-AD 200, was not just a lacklustre prelude for the marvels to follow, but an era that was cosmopolitan and complex in its own right.
‘In some areas, including near El Zotz, there are Preclassic settlements, and you can tell the difference’, says Tom, ‘because the structures look very different. There are rounded, more eroded shapes, which look kind of like pimples on the landscape, and stand out against the hard, angular shapes created by Classic structures. So there are places where the LiDAR lets you start to make a nice distinction. One thing that I have been looking at is a Preclassic settlement between El Zotz and Tikal, called El Palmar. We’ve been working there for a little while, and thought it was a minor site, but now the LiDAR has revealed that it’s 40 times larger than we suspected. That raises fundamental questions about how the region was developing during this period. We’d assumed that there wasn’t much else going on around Tikal as it developed into a major Preclassic settlement, but now you have to wonder whether El Palmar could have been a rival to Tikal. If so, why is it that one is abandoned and the other isn’t? At that point, you have to wonder if violence could have been involved.’
‘That could also be a factor when we look at the origins of El Zotz, which of course also lies close to Tikal. Both of these settlements were ancient Maya city-states, which had their own royal dynasties, but that doesn’t mean they were equal in scale. In that regard, comparing Tikal and El Zotz is a bit like comparing London with a provincial UK town. El Zotz was very much a minor power, and it seems as though it was subservient to Tikal for a while. Basically, El Zotz survived by allying itself with whoever was powerful at any given time. There’s been archaeological work at a part of El Zotz known as El Diablo since 2006, which I’ve been involved with since 2009. El Diablo is a hilltop that overlooks the rest of the town, and we now know this is where the Classic period started at El Zotz. We even found the tomb of the first king there in 2010.’
‘When we got the LiDAR data, it showed a series of terraces around El Diablo, and we made these proclamations saying, “Oh, it’s a fortress, these are defensive works”, but of course people might think that they were for agriculture, allowing the inhabitants to grow their crops on the hillside. So, as well as checking the LiDAR data on the ground and finding the earthworks, we needed to excavate to prove what they were. To do that, we dug big trenches along the earthworks, and fortunately it turned out that they were covered in plaster, which you wouldn’t do to your fields. We even found sling stones, which shows that these really were defences. It seems that the sling stones might have been a deliberate deposit, as it certainly wouldn’t be unheard of for the Maya to cache something away that was important to them. There was a cut in the plaster, which held a couple of hundred sling stones, with a bowl over-turned on top of them. So it seems like this city and kingdom was founded in fear, and the first thing they did was establish a palace on a heavily defended hilltop.’
A unique site
It was once thought that the Maya lived together in a state of relatively peaceful harmony. This narrative began to break down in the 1940s, when murals showing pretty graphic violence began to be discovered. Even then, it was felt that this pointed more to elite ritual warfare, with captives meeting a grisly end as sacrificial victims. Deciphering the Mayan texts added macabre details such as accounts of skulls being piled up, suggesting that more people might have been involved than was previously suspected. But even though the last 80 years have seen the peaceful Maya myth gradually replaced by something more violent and, sadly, more familiar from other, comparable societies, the numbers of military-style structures visible in the LiDAR data was still a revelation.
‘It shows state-level Maya military sophistication that we really hadn’t expected,’ Tom says. ‘An example is a site at La Cuernavilla, which is also between El Zotz and Tikal. This was one of the big surprises. Most of the cool stuff in LiDAR – and I’m told this is a general rule – appears on the very edge of your data. If NCALM, the people who collect the data, had clipped it to the area that we’d actually requested, we never would have seen La Cuernavilla. But the plane still had the LiDAR turned on, so they threw in the extra data for us. We were very lucky that right on the edge of our data was a type of site that no one has really seen before: a fortress. In addition to our ongoing support from the PACUNAM Foundation, my colleague Stephen Houston and I got funding from the US government – the National Science Foundation and the National Endowment for the Humanities – to do a three-year dig to try to understand it better. We’re calling it a fortress because it has big ditch and rampart earthwork systems, but we need excavation to find out what’s going on inside, and we’re really excited about that.’
‘La Cuernavilla lies a little closer to El Zotz than Tikal. There’s a valley that runs between the two sites, and the fortress is on the northern ridge defining that valley. When you look at the scale of the earthworks, you do wonder whether they really were worried about being attacked, or whether this could be a show of force. The defences are so over-built they seem to be saying “Don’t you even dare!” It’s also interesting to think about how La Cuernavilla fits into the relationship between El Zotz and Tikal. We know that Tikal was conquered by foreigners from the city of Teotihuacan in central Mexico during the 4th century. When I did the first exploration of La Cuernavilla in 2017, I cleaned out a big looter trench from an illegal excavation. This allowed me to look at what the looters had cut through, and it had the architecture that goes with the central Mexican style.’
‘This is really interesting to us, because it makes us wonder whether this is a case of the invasion being facilitated by El Zotz, to get Tikal off their back. It’s after this episode that the centre of El Zotz shifts away from the heavily defended hilltop, which suggests some of the threat was alleviated for a while. Alternatively, could La Cuernavilla also date to after the invasion of Tikal? Might we be looking at the spearhead of this new central-Mexico-backed regime in Tikal as it moves out from the city and into the wider region? These are questions that we can only answer with excavation. This is the great thing about the LiDAR, and it’s not just happening for me, it’s across the whole area that’s been surveyed. We can start asking these new questions, questions that are more sophisticated. As archaeologists, we used to spend all of our time just trying to get a sense of what was there. Now we know what’s there. So we can take it to another level.’
The Foundation for Maya Cultural and Natural Heritage (PACUNAM) is a non-profit organisation committed to the preservation of Guatemala’s natural and cultural heritage through sustainable development for the benefit of future generations. Founded in 2006, the foundation fosters scientific research, conservation, and sustainable development, with a key focus on the Maya Biosphere Reserve, an area of 21,000km2 in northern Guatemala.
The LiDAR data was gathered by the National Center for Airborne Laser Mapping (NCALM), a research centre based at the University of Houston. It is operated in partnership with the University of California, Berkeley.
CWA is grateful to Tom Garrison, Marianne Hernandez, and Emily Turner.