Secrets Season 3 Episode 5 America's Lost Pyramid

Five hundred years before Columbus arrived, a metropolis flourished in North America. It was bigger than Paris and London and featured a towering pyramid that still stands today. What happened to this ancient mega-city and why has it remained one of Western archaeology's best-kept secrets? Using modern technology, we explore this lost empire and reveal its shocking past that marked the dramatic rise and fall of America's first great city.