The lost wonders of a jungle civilisation

The spectacular pyramids at Tikal rising above the Guatemalan rainforest. For centuries, such dense foliage has kept the Maya secrets well, but an extensive LiDAR survey has revealed just how much lies shrouded under the canopy. [Image: Dreamstime/Diego Grandi]

The deeds of royal dynasties presiding over Maya city-states in northern Guatemala can still be followed on ornate inscriptions raised in their name. But just how large were their dominions? Recent survey work has revealed that the Maya were far more populous and sophisticated than previously suspected. Tom Garrison told Matthew Symonds how follow-up fieldwork is revolutionising our knowledge of Maya state power.

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.

One of the great advantages of LiDAR is that it can even show familiar sites in a new way. [Image: Dreamstime/Matyas Rehak]

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.

Near the iconic plazas at Tikal, this 3D rendering reveals that two features once thought to be natural are instead further examples of the pyramids that punctuate the site.

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.’

Investigation of what appeared to be a single pyramid, identified on the LiDAR data covering the outskirts of the city of Witzna, led to the discovery of two further pyramids along a causeway leading out from the city.

‘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!’

The Maya city-state at El Zotz features a hilltop known as El Diablo, which overlooks the rest of the town and contained the tomb of its first king. LiDAR revealed that El Diablo was ringed by a series of terraces, which resembled defences. Sure enough, excavation revealed a cache of sling stones, casting new light on the circumstances under which El Zotz was founded.

‘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.’

This is an extract from an article featured in issue 96 of Current World ArchaeologyClick here for more information about subscribing to the magazine