A Mayan city lost in the dense jungle of southern Mexico has been revealed. The discovery took place in the southeastern state of Campeche and archaeologists have named it Valeriana after a nearby freshwater lagoon.
“The larger of Valeriana’s two monumental districts has all the hallmarks of a classic Mayan political capital: enclosed plazas connected by a wide causeway; temple pyramids; a ball field; a reservoir formed by damming an arroyo (a seasonal watercourse); and a likely E-Group assemblage, an architectural arrangement that generally indicates a founding date before 150 AD,” says the study, published in the magazine Antiquity.
Discovering the city did not require breaking through the jungle with machetes or patiently digging with brushes and spatulas. Also, researchers didn’t need measuring tapes, binoculars or compasses to find their way through the dense foliage. Instead, they used state-of-the-art technology: lasers, drones and satellite maps. With these tools, they discovered a city hidden for centuries beneath the dense Mexican jungle, unearthing pyramids, enclosed plazas and an ancient reservoir.
Luke Auld-Thomas, an anthropologist at Northern Arizona University, made the discovery. His analysis revealed a vast network of previously undiscovered settlements.
Auld-Thomas and his fellow researchers have managed to map the city beneath the jungle thanks to aerial laser scanning, better known as lidar (light detection and ranging), a remote sensing technique that uses pulsed lasers and other data collected from overpasses that can generate accurate three-dimensional models of surface features, revolutionizing the way archaeologists explore the hidden past.
Laser pulses generate a topographic map in a manner similar to how a bat uses echolocation: laser light is fired from an aircraft, bounces off objects on the ground and returns to the detector on the underside of the aircraft. Although in Mexico only a small portion of the pulses pass through the dense jungle, the large number of pulses emitted ensures that enough light reaches the ground, creating a map with a resolution of up to 1 meter. Based on the timing and intensity of the returning pulses, the detector can map the contours of the terrain, revealing hills, ditches and ancient ruins covered in vegetation. The technology is also integrated in autonomous cars to prevent accidents.
“For a long time, our understanding of the Mayan civilization was limited to an area of a few hundred square kilometers,” says Auld-Thomas. “This limited sample was obtained with great difficulty, with archaeologists painstakingly scouring every square meter and hacking away vegetation with machetes, only to discover that they were sitting on a pile of stones that might have been someone’s home 1,500 years ago.”