For decades, archeologists have kept their eyes down to the ground as they slashed through jungles, attempting to spot traces left by lost civilizations like the Khmer Empire in Cambodia and the Maya in Mexico and Central America.

It's painstaking work that took entire careers to complete.

But now, archeologists -- or at least their tools -- are taking to the skies.

A new remote-sensing technique called lidar, or light detection and ranging, can produce detailed models of any terrain, revealing secrets usually hidden by tree canopy and forest.

This laser mapping is increasing the speed and scale of archeological discoveries and has now revealed the earliest and largest ceremonial structure ever built by the Maya -- covering more ground than the Great Pyramid at Giza, Egypt.

"It is so huge horizontally that if you walk on the site, it looks like a part of natural landscape. You would not recognize its rectangular shape. But in lidar it came out nice," said Takeshi Inomata, a professor of anthropology at the University of Arizona and the lead author of a paper on the discovery, which published Wednesday in the journal Nature.

"Without lidar, we probably would recognize the importance of this site eventually. But it would have taken many seasons of laborious mapping on the ground," he said.

Called Aguada Fénix, this previously unknown Maya site in Tabasco, Mexico, was built between 1,000 BC and 800 BC. The huge elevated platform stands 10 to 15 meters above the surrounding area with nine causeways extending from the platform.

Inomata said its volume, 3.8 million cubic meters, is larger than the Great Pyramid of Giza, Egypt (2.6 million cubic meters) --- although it's much shorter than the pyramid.

The platform would have been used for for rituals and the team found jade axes and other precious objects in its center, said Inomata.