Laser Mapping Shows Ancient City in Mexico Contained 40,000 Buildings
Researchers used LiDAR scanning to reveal the sprawling metropolis of Angamuco
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When researchers first found Angamuco, an ancient city in western Mexico built by rivals of the Aztecs, back in 2007, they tried several methods to explore the site, including an on-the-ground approach.
While this yielded a finding of impressive architectural features, they quickly realized it would take them a decade to survey the entire area, much of it rugged terrain. So they turned to a laser mapping technique known as light detection and ranging or LiDAR scanning.
As Nicola Davis reports for the Guardian, using the scanning technology, the team, led by Chris Fisher, an archaeologist at Colorado State University, has now explored the full extent of the city, and found that Angamuco once had as many buildings as modern-day Manhattan.
Fisher presented his team’s latest findings last week at the American Association for the Advancement of Science's annual conference in Austin, Texas. He tells Smithsonian.com that the discovery underscores how much there is to learn about the area. “In the 21st century, everybody thinks we have everything figured out, and we still have so much to discover," he says. "It’s a pretty well-traveled part of Mexico, and during 2007, we were able to find this city the was undocumented.”
Angamuco once spanned 10 square miles, taking up an area twice the size of Tzintzuntzan, though the ancient city was not as densely populated. Researchers have also discovered that Angamuco had an unusual layout with pyramids and open plazas concentrated in eight zones at the city’s edges, rather than its center.
The city of Angamuco was once located near a lake in what is now the state of Michoacán. It was built by the Purépecha, a major civilization in central Mexico in the early 16th century, a rival to the Aztecs. The earliest evidence from the city include ceramic fragments dating back the 900 CE.
At its peak, the city was home to more than 100,000 people between about 1000 CE and 1350 CE, making it about the biggest city in western Mexico at the time, Fisher says in an interview with the Guardian's Davis.
The new findings come after years of progress. In 2010, the team was using rugged computers and specialized GPS receivers and had only uncovered a small portion of the site, which they believed spanned just 2 square miles, according to reporting by the Los Angeles Times at the time.
In 2011, they started using LiDAR scanning, which slowly began to reveal the much more complex city and culture that once resided in the area, which included pyramids, temples, road systems, ball courts and garden areas.
In 2014, they also found the remains of 37 individuals, a rare copper and bronze rattle which was still functioning, numerous ceramic vessels and other grave goods, according to a press release by Colorado State University.
Davis reports that about 1.5 square miles of architectural features found through LiDAR scans have so far been verified from excavations by a team on the ground.
Fisher says that his team are continuing to excavate at the site of Angamuco and expect many more revelations to come. “You could have an army of people there for 40 years and not run out of things to find,” he tells Smithsonian.com.