Their religion.
Of paramount importance to the Moundville Indian was his religion. The mounds, on which he worshiped, are enduring monuments to the strength and fervor of his faith. Tons and tons of clay, loam and sand he carried to form these towering structures. Atop the earth pyramids he built great wooden temples and special dwelling houses for chieftans and priests.
Ceremonies performed in the temples were elaborate and colorful. Priests attired in symbolic costumes, and bearing numerous esoteric accoutrements, directed the rituals. Ceremonial trappings included beautiful copper breast plates, shell gorgets, and stone discs and pendants, all delicately carved with intricate, allegorical designs. Among these designs were depictions of the skull and arm-bone, the hand and all-seeing eye, entwined rattlesnakes, and the horned or plumed serpent. Similar designs are found in the symbolic art of the Indians of Central America and Mexico, the Mayas and Aztecs.
PIPES WHICH THE MOUNDVILLE INDIANS MOLDED FROM CLAY.