Archaeologists using a sort of laser-based radar were able to map 80 square miles of jungle-covered terrain around Caracol—an ancient Mayan city in Belize—in just four days. Compare to decades' worth of bug-beset, physically grueling on-the-ground mapping, which failed to turn up evidence of house mounds, roads and farms the laser mapping spotted with ease.
I will give you a moment to "Woah".
Lidar (light detection and ranging) is a fun-to-say technology that uses information gathered via reflected laser pulses to produce 3-D images. To map Caracol, researchers rigged lidar up to a plane that flew back and forth over the site. Enough of the laser pulses reached the ground and pinged back to the plane that copious trees couldn't get in the way of accurate maps.
This isn't the first time archaeologists have used remote sensing technologies to study ancient civilizations, or the first time lidar has been used this way. (I'd recommend checking out the cool work Payson Sheets from the University of Colorado has done with NASA since the 1980s, using satellite and infrared photography to find Central American villages buried under volcanic ash.) What is different is scope of this project. In the past, particularly in tropical areas, remote sensing was something you used to spot features, like an indentation that could mark a roadway, which might not be visible from the surface. Then, you'd take that information and go do some proper digging. Remote sensing helped you find a site, but shovels and eyeballs did the real mapping.
Caracol is different. Here, technology isn't just augmenting traditional archaeology, it's kind of replacing it, to a certain extent. Now, we can know more, faster, and with less backbreaking labor.