I headed to the August 2010 DNC meeting in St. Louis a bit early, crossed the River, and spent a fascinating day at the Cahokia Mounds UNESCO World Heritage Site.  Cahokia is a Native American city from the Mississippian period, which was  inhabited from about A.D. 700 to 1400.   At its peak, from A.D. 1050 to 1200, the city covered nearly six square miles and 10,000 to 20,000 people lived there.  The site featured 120 earthen mounds and many remain, including 100 foot tall Monks Mound – the largest earthen pyramid in North America.  These projects required an undetermined number of people to dig, haul, and deposit the dirt.  The Mound overlooks a central plaza used for ceremonies, including playing chunkey (a game involving players rolling a stone disc and trying to mark its stopping point with thrown spears; betting was involved).  The city included numerous houses and some of the mounds (most of which have not been excavated) included burials and grave goods originating from the Florida to Michigan.  The site features an a recreated woodhenge (solar calender), a section of recreated stockadge, and an excellent visitor center and is shared by deer and wild turkeys.  We don’t know why people assembled, over time built this extraordinary city, and then abandoned it.   See VA Bookshelf.