These images show a lost city buried under the Mexican jungle. (Chris Fisher)
A new laser-mapping technology, called lidar, has been used to confirm a truly mind-blowing ancient city buried in western Mexico. Called Angamuco, researchers say that it has about 40,000 buildings. This is around the same amount of building foundations as there are in Manhattan, New York. Whoa!
The ancient metropolis was built in 900AD by the Purépecha. These people were rivals to the more well-known Aztecs. The two nations traded (and fought) with one another, but neither one was able to conquer the other. But thanks to discoveries like this, the Purépecha's days of being a lesser known culture may be coming to an end.
Laser-sharp focus
This image is marked to show various buildings in the city. (Chris Fisher)
At the heart of this discovery is lidar, which stands for "light detection and ranging scanning". Essentially, it is similar to radar and sonar, in that it allows the researcher to see something hidden to normal human vision or senses.
Where radar allows us to detect distant objects approach in the air, and sonar allows us to map the ocean floor, lidar uses laser pulses from a passing aircraft to map the ground below. This is especially useful in areas where there is dense foliage, or trees and plants. In other words, lidar is giving researchers the chance to find ancient cities hidden by the jungle. This video from archeologist Chris Fisher, shows what lidar can reveal (wait until the trees are "removed" halfway through the video).
Pyramids and plazas
In the case of Angamuco, the discovery has revealed thousands of homes, plazas, roads, gardens, and pyramids that date back many centuries. At the city's peak (between 1000 and 1350AD), researchers guess that it would've been home to around 100,000 people. (This is larger than it might sound — at this time in world history, very few cities are thought to have had 1 million people in them.)
The city covered about 26 square kilometres (10 square miles), which is about 40 times the size of Disneyland. The huge size makes it easy to understand why archeologists love lidar! Without this technology, all the excavation would've had to have been done by hand. That would've taken decades. And while humans will still have to dig to actually unearth artifacts and ruins, at least they now know where to look.
Do you believe that there are more ancient cities like Angamuco left to discover?
