Another ancient city has been found, thanks to that handy modern technology known as LIDAR.
A little more than a month after announcing a “new” Mayan community in Guatamala, scientists have announced a 1,000-year-old city in Mexico, just as densely built as modern Manhattan.
LIDAR waves from above, combined with GPS and other data, reveal a three-dimensional map of the landscape, hidden in dense foliage in western Mexico.
The Purépecha, a tribe that rivaled the better-known Aztech, built their metropolis about a half an hour’s drive from Morelia.
“To think that this massive city existed in the heartland of Mexico for all this time and nobody knew it was there is kind of amazing,” said Chris Fisher, an archaeologist at Colorado State University who presented the latest findings from the study at the conference of the American Association for the Advancement of Science in Austin, Texas.
While less well known than the Aztecs, the Purépecha were a major civilization in central Mexico in the early 16th century, before Europeans arrived. Purépecha cities included an imperial capital called Tzintzuntzan that lies on the edge of Lake Pátzcuaro in western Mexico, an area in which modern Purépecha communities still live.
The recently discovered city, known as Angamuco, was more than double the size of Tzintzuntzan – although probably not as densely populated – extending over 26 square kilometers of ground that was covered by a lava flow thousands of years ago.
“That is a huge area with a lot of people and a lot of architectural foundations that are represented,” said Fisher. “If you do the maths, all of a sudden you are talking about 40,000 building foundations up there, which is [about] the same number of building foundations that are on the island of Manhattan.”
The team also found that Angamuco has an unusual layout. Monuments such as pyramids and open plazas are largely concentrated in eight zones around the city’s edges, rather being located in one large city center.
More than 100,000 people are thought to have lived in Angamuco in its heyday between about 1000AD to 1350AD, making it “the biggest city that we know of right now in western Mexico during this period,” said Fisher.
First found by researchers in 2007, archeologists initially attempted to explore Angamuco using a traditional “boots on the ground” approach, resulting in the discovery of about 1,500 architectural features over each square kilometer surveyed. But the team soon realized the rugged terrain meant it would take at least a decade to map the whole area.
Instead, since 2011 the LIDAR technique has been used to map a 35km2 area, revealing an astonishing array of features at high resolution, from pyramids and temples to road systems, garden areas for growing food and even ball courts.
Physical excavations were undertaken at seven locations to shed further light on the site. But LIDAR technology will be what changes our understanding of the world, Fisher said.
“Everywhere you point the LIDAR instrument you find new stuff, and that is because we know so little about the archaeological universe in the Americas right now,” he said. “Right now every textbook has to be rewritten, and two years from now (they’re) going to have to be rewritten again.”
Fisher has also used LIDAR to explore a remote area of the Mosquitia region of north-eastern Honduras, at the City of the Jaguar. This settlement, the team found, had terraces, water control features such as canals, and about 10 plaza complexes, with the whole city stretching over three square kilometers.
“Many of these areas of the Americas that we see today that we think that we would classify as pristine tropical forests are really abandoned gardens,” says Fisher.
Naysayers object, countering that claims of a “lost city” smack of colonialist rhetoric.
Elizabeth Graham, professor of Mesoamerican archaeology at University College London who was not involved in the projects, said the team’s work was impressive, and that LIDAR was backing up long-held suspicions about the size of archaeological settlements.
“Once it shows all traces of the land surface, we can interpret those, because you can tell what is natural and what is not,” she added, in the London Guardian. “It’ll show you terracing, where houses are – or at least structures of some sort – agricultural features, manipulated land – all of that.”
Traditional techniques are still needed to unearth the details. “Ultimately we still have to get on the ground and then excavate,” she said.