The team used lidar technology to create three-dimensional models across 50 miles of land in Campeche, allowing them to map areas not visible to the naked eye.

The method revealed a 21-square-mile metropolis with iconic stone pyramids, houses and other infrastructure that have been concealed for more than 3,000 years.

There are hundreds of documented Mayan sites, but the newest find revealed that researchers aren't close to finding all the major Maya cities.

'Our analysis not only revealed a picture of a region that was dense with settlements, but it also revealed a lot of variability,' said the study's co-author, Luke Auld-Thomas, a doctoral student at Tulane University.

'We didn't just find rural areas and smaller settlements. We also found a large city with pyramids right next to the area's only highway, near a town where people have been actively farming among the ruins for years,' Auld-Thomas said. 

The team conducted an aerial lidar survey, which uses laser pulses to measure distances and create three-dimensional models of specific areas. 

It has allowed scientists to scan large swaths of land from the comfort of a computer lab, uncovering anomalies in the landscape that often prove to be pyramids, family houses and other examples Maya infrastructure. 

'Because lidar allows us to map large areas very quickly, and at really high precision and levels of detail, that made us react, 'Oh wow, there are so many buildings out there we didn't know about, the population must have been huge,' Auld-Thomas said. 

'The counterargument was that lidar surveys were still too tethered to known, large sites, such as Tikal, and therefore had developed a distorted image of the Maya lowlands. 

'What if the rest of the Maya area was far more rural and what we had mapped so far was the exception instead of the rule?' 

The team uncovered two blocks of the Mayan city, one of which included a distinct pseudo-pyramid that was identical to one found at Rio Bec - a pre-Columbian Mayan archaeological site located near the Guatemala border in the Yucatan Peninsula.