"Amazonia is not the “wilderness” many assume it to be. For thousands of years human beings have been residing in and cultivating lowland and upland areas across the Amazon basin and beyond.
A recent article in National Geographic News provides a glimpse of earthworks built long before Columbus. Rediscoveries of the ancient croplands and city sites force us to re-evaluate notions of wilderness and to consider the long-standing, organized, cultural interactions and influences of humanity upon western landscapes."
http://westinstenv.org/sosf/2010/01/08/ancient-amazon-earthworks-seen-by-satellite/
http://news.nationalgeographic.com/news/2010/01/100104-amazon-lost-civilization-circles.html
http://archaeologynewsnetwork.blogspot.com/2010/11/amazonian-geoglyphs.html
