There are similarities among the mounds in the Lower Mississippi Valley, but there are also significant differences. Shapes vary, including flat-topped pyramids, cones, ovals, loafs, and barely perceptible rises in the dirt.
Mounds stand alone and in clusters.
Some clusters are scattered across broad plazas, while others are connected by raised paths. Signs of stockades and ditch fortifications enclosing some mounds imply warfare. No discernible defenses at other sites suggest peaceful periods. How Native Americans used the mounds also varied, with some of the most ancient purposes shrouded in mystery. Early people buried their dead with great solemnity and ceremony in some of the mounds.