Archaeologists have discovered hundreds of ancient, monumental designs carved in the earth that hint at complex societies in the Amazon rainforest a millennium before Spanish and Portuguese colonists arrived. See the formations, some of which are more than 2,500 years old, here.

nyti.msArchaeologists Find Hundreds of Ancient Glyphs in the AmazonThe geometric earthwork structures, carved into the ground with embankments and ditches, are in some cases more than 2,500 years old, researchers said.