Cahokia

When spring and autumn arrived in the ancient city of Cahokia, the city’s chief reaffirmed his connection to the cosmos. On the equinoxes, priests watched the sunrise from inside a ring of tall poles that served as a calendar. They saw the Sun climb into view behind Monks Mound, a great pile of earth topped by the chief’s home and court. The Sun was reborn — and so was the chief.
Cahokia stands across the Mississippi River from present-day Saint Louis. The city reached its peak around eight centuries ago. It covered about six square miles, incorporated more than a hundred earthen mounds, and its population swelled to perhaps 20,000 — larger than London.
The focal point for Cahokia was Monks Mound — the largest earthen structure in the early Americas. It covered 14 acres and rose a hundred feet into the sky. Most of it is still standing.
To the west of the mound, inhabitants built a calendar circle. Archaeologists named it Woodhenge because of its resemblance to Stonehenge. The Cahokian