Oblivious to its historical value, workers needing fill dirt ... A ten-story behemoth known as Monks Mound is the centerpiece of the 2,200 acre Cahokia Mounds State Historic Site.

The ancient North American city of Cahokia had as its focal point a feature now known as Monks Mound, a giant earthwork surrounded on its north, south, east and west by large rectangular open areas.