Researchers believe they may finally have uncovered the lost 'White City of gold' in Honduras using hi-tech scanners that let aircraft 'see' through dense forest.Researchers from the University of Houston and the National Center for Airborne Laser Mapping (NCALM) flew over the Mosquitia region in a small plane shooting billions of laser pulses at the ground to create a 3D digital map of the topology beneath the jungle canopy.

Compiling their data, the analysts revealed what appears to be man-made elevation changes that are thought to show a forgotten city plaza dotted with pyramids reclaimed by the jungle.
© University of HoustonThe University of Houston and National Center for Airborne Laser Mapping team produced this 3D digital topological map which when examined shows a man-made plaza ringed in red

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According to legend, Ciudad Blanca or the 'White City' is full of gold and has been sought out by explorers and treasure hunters since conquistador Hernando Cortes first made reference to it in a 1526 letter to King Charles V of Spain.

Inspired by this legend, cinematographer and Ciudad Blanca enthusiast Steven Elkins sought backing from private investors to pay for the team at NCLAM to use their laser mapping technology to chart the forest floor of Mosquitia.

Over the course of a week, the NCALM and University of Houston engineers flew over 60 square miles of forest in their dual-engine Cessna planes.

LiDAR's computer-generated images allow researchers to 'see' through the forest canopy to the ground surface, revealing any evidence of ancient settlements or human-engineered landscapes.

'The LiDAR point cloud data clearly show the remains of large settlements that can be characterized as ancient cities based on their spatial complexity, size and organization,' said Colorado State University professors Christopher Fisher, who led the research.

'We may never be able to tell whether any of these are Ciudad Blanca, or whether the legendary city ever existed, but we can clearly see in the UTL data evidence that there was a densely settled region with a human modified environment.

'These conclusions provide important new insights into the pre-Hispanic settlement of this largely unexplored region.'

This was one of the first times that laser mapping, specifically light detection and ranging (LiDAR) had been used to locate ancient ruins.

The original uses of the technology were to provide intelligence after earthquakes, military spying and for river erosion detection.

Flying above the intended target area, LiDAR operates by sending out 100,000 short laser pulses to the ground each second.

The University of Houston and the NCALM team blanketed the Mosquitia rainforest with as many as 25-50 laser pulses every square metre that totaled up as more than four billion shots during the entire project.

Like a high-tech version of sonar, the light beams hit the ground and return to the aircraft and the time taken allows researchers to create 3D digital map of the surrounding topology.

Able to differentiate between differences in height of less than four inches, the University of Houston has worked with the NCALM to develop their LiDAR systems.

Ciudad Blanca has played a central role in Central American mythology.

Text's cite it as the birthplace of the Aztec god Quetzalcoatl and previous reported sightings over the years have described golden idols and elaborately carved white stones, leading to the lost city's name.

However, no confirmation of the existence of the city has ever been provided.

If confirmed, the discovery of Ciudad Blanca would be comparable to the popularisation of forgotten sites such as Machu Picchu, which lay ruined for hundreds of years until reintroduced to western eyes in 1911 by American historian Hiram Bingham.

And if the myth is dispelled, any positive identification of the fabled 'White City' of Ciudad Blanca would reignite hopes of finding the legendary 'Lost City of Gold', El Dorado.

While the news of the encouraging results this week were greeted favourably by Honduran President Porfirio Lobo, archaeologists will now have to undertake a trek through the dense forest to visit the site in person.