Network of Fortified Towns Indicates Amazon Was Once Heavily Populated

Today we think of the Amazon as a pristine rainforest, sparsely populated by indigenous communities. But in records from the 1500s, Spanish colonizers describe a densely populated region, crisscrossed by canals and sunken roads and dotted with bustling, fortified towns. Unfortunately, fortification couldn’t protect the towns’ inhabitants against European diseases, which devastated South American indigenous populations and left the fortified villages abandoned.

Source: arstechnica.com