Tom Clynes, National Geographic:

The project mapped more than 800 square miles (2,100 square kilometers) of the Maya Biosphere Reserve in the Petén region of Guatemala, producing the largest LiDAR data set ever obtained for archaeological research.

The results suggest that Central America supported an advanced civilization that was, at its peak some 1,200 years ago, more comparable to sophisticated cultures such as ancient Greece or China than to the scattered and sparsely populated city states that ground-based research had long suggested.

In addition to hundreds of previously unknown structures, the LiDAR images show raised highways connecting urban centers and quarries. Complex irrigation and terracing systems supported intensive agriculture capable of feeding masses of workers who dramatically reshaped the landscape.

More:

Lasers Reveal a Maya Civilization So Dense It Blew Experts’ Minds – Jacey Fortin, The New York Times

Laser Scans Reveal 60,000 Hidden Maya Structures in Guatemala – Smithsonian

Maya civilization was much vaster than known, thousands of newly discovered structures reveal – Cleve R. Wootson Jr., Washington Post

Huge Mayan city with pyramids found hidden under jungle – Associated Press via CBC