In the ongoing quest to unearth the world's hidden mysteries, University of Houston researchers and archaeology partners have discovered a lost Maya city deep in the jungles of Campeche, on the Yucatan Peninsula, in Mexico. Their track record includes finding ruins in 2012 in Eastern Honduras where centuries-old legends talk of a "lost white city". The 2016 mapping of more than 80,000 Maya structures including many previously unknown Maya settlements and agricultural and defensive structures in the Guatemalan Peten jungle.

In terms of exploration, NCALM researchers get the first bite at the apple. Flying high above sites of interest, their plane armed with airborne light detection and ranging (lidar) equipment, they scan the vast array of landforms. Lidar allows unprecedented data collection in areas that are extremely difficult to enter on foot, like deep within jungles and rainforests. "You can compare us to ultrasound technicians. We are the first to see the baby, but the doctor will tell you all about it and confirm the findings," said Juan Carlos Fernandez-Diaz, co-principal investigator of NCALM, housed in the Cullen College of Engineering, where he is also a research assistant professor of civil and environmental engineering.

Using lidar technology, Fernandez-Diaz and his team shoot hundreds of thousands of laser bursts per second at the ground and measure how quickly those pulses hit the ground and bounce back to their source. Those calculations reveal the exact distance between the plane and the ground. By repeating that process several billion times, the explorers create a three-dimensional map, complete with topographical markings noting rising structures and other hidden gems. They believe it is second in size only to Calakmul, thought to be the largest Mayan site in ancient Latin America.

It was a Lidar survey, a remote sensing technique that fires thousands of radar pulses from a plane and maps objects below using the time the signal takes to return. But when Mr Auld-Thomas processed the data with methods used by archaeologists, he saw what others had missed - a huge ancient city that may have been home to 30-50,000 people at its peak from 750 to 850 AD. That is more than the number of people who live in the region today, the researchers say. Mr Auld-Thomas and his colleagues named the city Valeriana after a nearby lagoon. This accidental discovery of a lost city not only highlights the serendipity often found in scientific research but also emphasizes the importance of interdisciplinary approaches in archaeology.