Pyramid (truncated) mounds were used for ceremonies as well as platforms for home of the elite. Pyramid mounds were created primarily by the Mississippian Culture throughout the Midwest and southern United States.
The Cahokia Mounds State Historic Site is located along the Mississippi River in western Illinois across from Saint Louis. This site is well maintained by the Illinois Historic Preservation Agency. Cahokia was the largest centers in the United States as well as boasts has the tallest mound (Monks Mound). The agency preserves 68 of the original 120 mounds. There are guided tours in the summer, a nature trail and three self guided interpretive trails for the plaza, Monks Mound and Woodhenge. The interpretive center is one of the best I’ve been to. The staff and tour guides are very knowledgeable.
Emerald Mound was the center of a ceremonial center occupied from 1250 to 1600AD. Emerald Mound is one of the largest mounds in the United States covering eight acres and 35 feet high. There are two smaller mounds on top of Emerald and at one time there were several around the base but were destroyed from development. The mound is located about ten miles northeast of Natchez, Mississippi on the Natchez Trace Parkway.
Angel Mounds is located southeast of Evansville, Indiana overlooking the Ohio River. The complex was built around 1000AD and was abandoned by 1450AD. It is one of the best preserved prehistoric Native American sites in the United States. There are seven mounds in two complexes with Central Mound as the highest in the complex. There is also an example of a stockade wall and an interpretive center.