All we think of is the Inca, who didn't even start their rise to power till about 1450.
I highly recommend the book 1491, a discussion of the pre-Columbus history of the Americas. Large areas of the continent that we assume were largely uninhabited prior to the arrival of the white man actually supported massive populations, including much of the Amazon.
These civilizations were wiped out by the epidemics created when the American and Afro-Eurasian disease ecosystems merged, reducing the population of the western hemisphere by 1600 by possibly over 90%.
The problem is this.
These huge areas of terraforming and architectural phenomena are so huge, it makes the great pyramids look like Lincoln Logs.
People marvel at the Nazca images, but that is not even a drop in the bucket compared to all these excavations.
No language? No culture? No cities? No ceramics?
What the heck is this all about?
Good book.
Posted to FR nine years ago:
What do you mean by massive?
IMHO, such excavations might occur over decades to centuries with natural processes such as those which form Seifs in the desert.
They aren’t used today, because we can use heavy equipment to develop the terrain so much more quickly, without much intellectual design into the method of work.