Archaeologists have discovered a complex system of ancient cities in the Amazon rainforest, dating back nearly 3,000 years.

The discovery, which includes pyramids, palaces, and a ball court, was made possible by the Ecuadorean government’s use of lidar technology, which allows for the survey of dense forested areas and the creation of accurate maps in a fraction of the time.

This discovery is the oldest and largest of its kind in the region.