Scattered across North America are enormous, mysterious earthworks that have been linked to everything from vanished Native American tribes to extraterrestrial visits, the fabled continent of Atlantis, and even a mysterious race of towering giants.

The legacy of ancient civilizations often lies in the structures they leave behind, and this is especially true of the mound-building societies whose obsessive construction of these cryptic mounds has left historians and archeologists baffled for ages.

Far from mere piles of earth, many of these mounds showcase advanced geometric designs, precise celestial alignments, and unparalleled mathematical precision. Such sophistication has led some to suggest that these ancient mound-builders may have held knowledge in specific areas that even surpasses our own.

Yet, these architectural wonders pose more questions than they answer. What purpose did they serve? And why did the masterful builders behind them seemingly vanish without a trace?

This is the story of North America's ancient mound-builders and the centuries-long quest to piece together the puzzle of their creations...