An aerial survey over northern Guatemala has turned up over 60,000 new Maya structures, including pyramids, causeways, house foundations and defensive fortifications. 
 
 It's a watershed discovery that has already led archaeologists to new sites to excavate and explore. The findings may also revise estimates of how many ancient Maya once lived in the region upward by "multiple factors," said Tom Garrison, an archaeologist who specializes in the Maya culture and is part of the consortium that funded and organized the survey. Far more ancient Maya lived on the landscape than there are people in the region today, Garrison told Live Science, and they did it without the destructive slash-and-burn agriculture that is crippling the jungle in modern times. 
 
 The finding of a sprawling Maya population shows there are means of supporting people in the area without destroying the forest, said Lisa Lucero, an anthropologist at the University of Illinois who was not involved in the new survey. [See Images of the Amazing Maya Discoveries] 
 
 Seeing the evidence of that sprawling population requires stripping away the forest — at least virtually. The new survey used a technology called lidar, which stands for "light detection and ranging." It works by beaming laser pulses at the ground — in this case, from airplanes — and measuring the wavelengths as they bounce back to create a detailed three-dimensional image of the stuff on the ground. It's a little bit like the sonar that bats use to hunt, except it uses light waves instead of sound. 
 
 "Lidar is magic," Lucero told Live Science. In the densely forested Maya lowlands of Guatemala, it's easy to walk right by an archaeological mound or feature and miss it entirely. Lidar maps the topography with such precision that rectangular features — like roads, house foundations and plazas — just "pop out," said David Stuart, a University of Texas at Austin anthropologist who has followed the new lidar mapping project closely. 
 
 Garrison's experience bears that out. He and his colleagues have been excavating a Maya site called El Zotz in northern Guatemala, painstakingly mapping the landscape for years. The lidar survey revealed a 30-foot-long (9 meters) fortification wall that the team had never noticed before. [Images: Maya Maize Secrets Revealed in Tikal Soil] 
 
 "Maybe, eventually, we would have gotten to this hilltop where this fortress is, but I was within about 150 feet [46 m] of it in 2010 and didn't see anything," he told Live Science. 
 
 Garrison visited the dirt wall in person in June, and he and his team are now seeking funding to excavate there, he said. The discovery of the fortification suggests that Maya warfare was not a matter of small, intermittent skirmishes, but serious battles. 
 
 "This is investment in the landscape," he said of the wall. 
 
 Lidar was first used in archaeology in 1985 in Costa Rica, but it wasn't until 2009, when researchers used it to survey a site in Belize, that it came to the region the Maya once inhabited. 
 
 Lidar "is to the 21st century what radiocarbon dating was to archaeology in the last century," said Payson Sheets, who led the Costa Rica excavation where lidar was first deployed. "It's revolutionary," said Sheets, who is a Mesoamerica anthropologist at the University of Colorado Boulder. 
 
 The new effort was led by Guatemala's PACUNAM LiDAR Initiative and was funded by the PACUNAM Foundation. Aerial surveys scanned 810 square miles (2,100 square kilometers) over 10 separate areas of northern Guatemala, some of which had been mapped by hand and some of which were largely unexplored. They found more than 60,000 architectural mound structures. Most, Garrison said, are probably stone platforms that supported the pole-and-thatch homes of average Maya people. But the surveys also turned up features that are probably pyramids, causeways and defenses. 
 
 A National Geographic special, "Lost Treasures of the Maya Snake Kings," will focus on some of these finds, including a seven-story pyramid so covered in vegetation that it practically melts into the jungle. The documentary premieres Tuesday, Feb. 6 at 9 p.m. EST/8 p.m. CST. 
 
 One intriguing feature on the lidar maps, Lucero said, is how many roads the Maya built. They did not use beasts of burden, she said, so these roads wouldn't have served as pathways for carts or wagons. They may have functioned as causeways during the swampy rainy season, she said, or as platforms for processions. 
 
 Also fascinating, Stuart said, are the blank spots on the lidar — the places the Maya chose not to live. No one wants to survey a blank area, he said, but the Maya were sophisticated users of the landscape, and their choices about where to settle might reveal more about how they farmed and used water. 
 
 "It's going to change our views of population and just on how the Maya lived on that landscape," Stuart said. "By having this more accurate picture of what is there, we can start to talk about community organization, agricultural systems land use, roadways and communication." 
 
 Original article on Live Science. ||||| GUATEMALA CITY (Reuters) - Thousands of previously unknown ancient Maya structures, including pyramids, palaces and causeways, have been revealed in Guatemala following an investigation by a team of international archaeologists using ground-penetrating laser technology. 
 
 The find allowed the researchers to map the outlines of what they describe as dozens of newly discovered Maya cities hidden under thick jungle foliage centuries after they were abandoned by their original inhabitants, according to a statement issued on Thursday by Guatemala’s PACUNAM foundation. 
 
 The ancient Maya civilization was one of the most advanced to arise in Mesoamerica, marked by sophisticated mathematics and engineering that allowed it to spread throughout present-day Central America and southern Mexico. 
 
 The research used so-called LIDAR technology that utilizes light from lasers to construct a detailed survey of buried structures. 
 
 “The fortified structures and large causeways reveal modifications to the natural landscape made by the Maya on a previously unimaginable scale,” said Francisco Estrada-Belli of Tulane University. 
 
 The team of archaeologists surveyed more than 810 square miles (2,100 sq km) of the Peten jungle and even revealed a pyramid in the heart of the ancient Maya city of Tikal, a major tourist destination in northeastern Guatemala. 
 
 The pyramid measures nearly 100 feet (30 meters) tall and was previously thought to be a small mountain. 
 
 The earliest Maya settlements were constructed around 1,000 B.C., and most major Maya cities collapsed by 900 A.D. The cause of the collapse remains the focus of intense academic debate. ||||| Learn how your family history is connected to the human journey with National Geographic’s Geno 2.0 DNA ancestry kit. 
 
 Using a revolutionary technology known as LiDAR (short for “Light Detection And Ranging”), scholars digitally removed the tree canopy from aerial images of the now-unpopulated landscape, revealing the ruins of a sprawling pre-Columbian civilization that was far more complex and interconnected than most Maya specialists had supposed. 
 
 “The LiDAR images make it clear that this entire region was a settlement system whose scale and population density had been grossly underestimated,” said Thomas Garrison, an Ithaca College archaeologist and National Geographic Explorer who specializes in using digital technology for archaeological research. 
 
 Watch a preview for "Lost Treasures of the Maya Snake Kings." 
 
 National Geographic Channel 
 
 Garrison is part of a consortium of researchers who are participating in the project, which was spearheaded by the PACUNAM Foundation, a Guatemalan nonprofit that fosters scientific research, sustainable development, and cultural heritage preservation. 
 
 The project mapped more than 800 square miles (2,100 square kilometers) of the Maya Biosphere Reserve in the Petén region of Guatemala, producing the largest LiDAR data set ever obtained for archaeological research. 
 
 MAPPING THE MAYA WORLD Researchers using aerial lidar sensing equipment targeted 10 parcels within Guatemala’s Maya Biosphere Reserve. Their discoveries are revealing previously unknown areas of Maya cities. AREA ENLARGED MAYA REGION 20 mi XMAKABATUN 20 km WITZNA TIKAL HOLMUL GUATEMALA MEXICO Mayan cities Targeted lidar zones Current forest cover SOREN WALLJASPER, NG STAFF SOURCE: WILD BLUE MEDIA/NATIONAL GEOGRAPHIC MAPPING THE MAYA WORLD Researchers using aerial lidar sensing equipment targeted 10 parcels within Guatemala’s Maya Biosphere Reserve. Their discoveries are revealing previously unknown areas of Maya cities. XMAKABATUN MEXICO WITZNA HOLMUL TIKAL GUATEMALA Maya City AREA ENLARGED Lidar Study Area 20 mi MAYA REGION 20 km SOREN WALLJASPER, NG STAFF SOURCE: WILD BLUE MEDIA/NATIONAL GEOGRAPHIC 
 
 The results suggest that Central America supported an advanced civilization that was, at its peak some 1,200 years ago, more comparable to sophisticated cultures such as ancient Greece or China than to the scattered and sparsely populated city states that ground-based research had long suggested. 
 
 In addition to hundreds of previously unknown structures, the LiDAR images show raised highways connecting urban centers and quarries. Complex irrigation and terracing systems supported intensive agriculture capable of feeding masses of workers who dramatically reshaped the landscape. 
 
 The ancient Maya never used the wheel or beasts of burden, yet “this was a civilization that was literally moving mountains,” said Marcello Canuto, a Tulane University archaeologist and National Geographic Explorer who participated in the project. 
 
 “We’ve had this western conceit that complex civilizations can’t flourish in the tropics, that the tropics are where civilizations go to die,” said Canuto, who conducts archaeological research at a Guatemalan site known as La Corona. “But with the new LiDAR-based evidence from Central America and [Cambodia’s] Angkor Wat, we now have to consider that complex societies may have formed in the tropics and made their way outward from there.” 
 
 Surprising Insights 
 
 “LiDAR is revolutionizing archaeology the way the Hubble Space Telescope revolutionized astronomy,” said Francisco Estrada-Belli, a Tulane University archaeologist and National Geographic Explorer. “We’ll need 100 years to go through all [the data] and really understand what we’re seeing.” 
 
 Already, though, the survey has yielded surprising insights into settlement patterns, inter-urban connectivity, and militarization in the Maya Lowlands. At its peak in the Maya classic period (approximately A.D. 250–900), the civilization covered an area about twice the size of medieval England, but it was far more densely populated. 
 
 “Most people had been comfortable with population estimates of around 5 million,” said Estrada-Belli, who directs a multi-disciplinary archaeological project at Holmul, Guatemala. “With this new data it’s no longer unreasonable to think that there were 10 to 15 million people there—including many living in low-lying, swampy areas that many of us had thought uninhabitable.” 
 
 Virtually all the Mayan cities were connected by causeways wide enough to suggest that they were heavily trafficked and used for trade and other forms of regional interaction. These highways were elevated to allow easy passage even during rainy seasons. In a part of the world where there is usually too much or too little precipitation, the flow of water was meticulously planned and controlled via canals, dikes, and reservoirs. 
 
 Among the most surprising findings was the ubiquity of defensive walls, ramparts, terraces, and fortresses. “Warfare wasn’t only happening toward the end of the civilization,” said Garrison. “It was large-scale and systematic, and it endured over many years.” 
 
 View Images Laser scans revealed more than 60,000 previously unknown Maya structures that were part of a vast network of cities, fortifications, farms, and highways. Courtesy Wild Blue Media/National Geographic 
 
 The survey also revealed thousands of pits dug by modern-day looters. “Many of these new sites are only new to us; they are not new to looters,” said Marianne Hernandez, president of the PACUNAM Foundation. (Read "Losing Maya Heritage to Looters.") 
 
 Environmental degradation is another concern. Guatemala is losing more than 10 percent of its forests annually, and habitat loss has accelerated along its border with Mexico as trespassers burn and clear land for agriculture and human settlement. 
 
 “By identifying these sites and helping to understand who these ancient people were, we hope to raise awareness of the value of protecting these places,” Hernandez said. 
 
 The survey is the first phase of the PACUNAM LiDAR Initiative, a three-year project that will eventually map more than 5,000 square miles (14,000 square kilometers) of Guatemala’s lowlands, part of a pre-Columbian settlement system that extended north to the Gulf of Mexico. 
 
 View Images Hidden deep in the jungle, the newly-discovered pyramid rises some seven stories high but is nearly invisible to the naked eye. Photograph by Wild Blue Media/National Geographic
– Only a handful of ancient Mayan temples rise above a dense jungle of trees in Guatemala. But what's obscured by the thick foliage, revealed for the first time, is evidence of a sprawling civilization to rival ancient Greece or China. Using LiDAR technology (Light Detection And Ranging), which measures wavelengths from laser pulses aimed at the ground, scientists digitally removed the jungle to reveal more than 60,000 previously unknown Mayan structures like palaces, fortifications, farms, irrigation systems, and raised highways connecting nearly all ancient cities across 800 square miles in northern Guatemala, report Live Science and National Geographic. "We'll need 100 years to go through all [the data] and really understand what we're seeing," says researcher Francisco Estrada-Belli. But already it's apparent that the civilization has been "grossly underestimated," says archaeologist Thomas Garrison. The new data show a civilization twice the size of medieval England at its peak 1,200 years ago. And though population estimates previously hovered around 5 million, expansive irrigation and terracing systems and wide highways indicate there might've been "10 to 15 million people there—including many living in low-lying, swampy areas that many of us had thought uninhabitable," Estrada-Belli says. Walls, fortresses, and ramparts also suggest war was "large-scale and systematic" and "endured over many years" not just "toward the end of the civilization," says Garrison. One of the coolest discoveries, however, was a 100-foot pyramid in the heart of the city of Tikal, which was previously assumed to be a small mountain, reports Reuters. More discoveries are likely to be made as scientists plan to map 5,000 square miles of Guatemala's lowlands during the ongoing project. (The Maya parried one collapse before the fatal blow.)