The Great Temple Mound, also known as the Monks Mound, is the largest earthen structure in North America, located in Cahokia Mounds State Historic Site near Collinsville, Illinois. Built by the Mississippian culture around 1000 AD, it stands approximately 100 feet tall and covers 14 acres. The mound served as a platform for a temple and was central to the religious and political life of the Cahokian society. The Great Temple Mound is part of a larger complex of mounds and earthworks that reflect the advanced engineering and social organization of the Cahokia civilization. It is a UNESCO World Heritage Site, recognized for its historical significance and the insights it provides into pre-Columbian North America.