Two articles about the Maya civilization:
Seeker article about LiDAR being used to reveal ancient structures on the Jungle ground: A network of 150km of prehistoric Autobahn ran through the Jungle, binding the Mayan Empire together.
“These causeways are 130 feet wide, up to 20 feet high and in some cases they extend as far as 25 miles,” Hansen said.
A causeway is a raised road across difficult, often wet or unstable ground. Because of the raised structure LiDAR can find these roads even today.