Lost cities of the Amazon

OK, we're not talking about the legendary cities of gold that lured explorers like Percy Fawcett to their deaths. But this is an interesting story nonetheless. An area of the Amazon river basin thought of as virgin forest inhabited only by hunter-gatherers of the Kuikuro tribe has yielded the remains of well-organized towns from the 15th century. The Upper Xingu region was host to a network of towns up to 60 hectares in area, each organized around a central plaza and surrounded by earthworks. Inhabitants engaged in agriculture and likely aquaculture (fish farming). The towns may have been decimated by disease or may have been attacked by early Europeans, although no records of contact have been found.