Monks Mound, the largest pre-Columbian earthwork in the Americas. Rectangular in form, it contains an estimated 22 million cubic feet of earth. All of this soil was dug by hand and carried using baskets and bags filled with approximately 40 pounds of soil. The base covers more than 14 acres, and it rises to a height of 100 feet. Today it consists of four terraces, each with its own characteristics and history. A massive building once stood on the summit where the principal chief would live, conduct ceremonies, and govern. Visitors can walk up the 156 steps leading to the top. From there, the Grand Plaza and Twin Mounds would be in view, as well as the city of St. Louis in the distance to the west.