Located northeast of Natchez, Mississippi along the Natchez Trace Parkway, Emerald Mound is the second largest prehistoric earthwork in the United States. The Mississippian ancestors of the historically-known Natchez Indians reshaped a natural hill into a platform having angled sides and a flat top almost 8 acres in area, and then built smaller "secondary" mounds atop the main mound. Two of these remain, at its opposite ends. Here's the view from the larger secondary mound to the smaller one, across the platform.
Down at the other end, atop the smaller secondary mound, looking back at the larger one.
This is a side view of the larger secondary mound. Although this mound dwarfs the people standing on it or using the modern stairway, it's still tiny compared to the primary mound on which it sits.