Secrets Unlocked S01E19 - America's Lost Pyramid

Over 1,000 years ago, a great civilization built a thriving metropolis that was larger than medieval Paris, London and Rome. At its heart was a pyramid that rivaled those of Egypt. But this mighty city was not in Europe or anywhere in the East. It was in North America. Join us as we explore ancient Cahokia, one of the most astonishing mysteries of Western archeology. Using cutting-edge technology, we unravel its secrets and reveal the turbulent events that marked the dramatic rise and fall of America's first great city.