Collinsville, Madison County, Illinois, USA, United States of America
Cahokia Mounds is the largest pre-Columbian settlement north of Mexico, a planned city that at its peak around 1100 CE housed between 10,000 and 20,000 people — larger than contemporary London — built entirely without metal tools, wheeled vehicles, or draft animals. Its centrepiece, Monks Mound, contains more earth than the Great Pyramid of Giza and was constructed entirely by hand-transported basket loads of soil. The city was abandoned around 1350 CE for reasons still debated, and its builders have no confirmed modern descendants. It is the most important and least known archaeological site in North America.
Mississippian culture city flourishing approximately 900 to 1350 CE; peak population approximately 1050 to 1150 CE; UNESCO inscribed 1982
