A series of ring-shaped ditches can be found throughout the Brazilian Amazon, which predate the rain forest itself. These structures remain a complete mystery, and archaeologists are unsure what to make of them. It is suggested that they served as burial grounds or a form of defense, but no one knows for sure.
With Molly Brandenburg & Richard Rossner
About Unexplained Mysteries
“We don’t know.” answers too many questions. But in this podcast, we don’t take “we don’t know” for an answer. Every Thursday, Unexplained Mysteries investigates the greatest mysteries of history and life on earth, because the answer “we don’t know” is always the scariest. Unexplained Mysteries is part of the Parcast Network and is a Cutler Media production. Ad-free archives of episodes six months or older are now available through Stitcher Premium.