Well, Monks Mound is the largest Pre-Columbian earthwork in the Americas and the largest pyramid north of Mesoamerica. In 1988, Monks Mound size was about 100 feet height, 955 feet long. The Mound is located at the Cahokia Mounds UNESCO World Heritage Site near Collinsville, Illinois. The Monks Mound base circumference is larger than the Pyramid of Sun at Teotihuacan and roughly same size of Great Pyramid of Giza 13.1 acres. However, Egyptian Pyramids built with stones in contrast of platform mound was constructed entirely layers of basket transported soil and clay. Due to flattened top, the rainwater accumulated within the structure result in slumping, the avalanche-like sliding of large sections of the sides at the highest part of the mound.
The recent excavations have exposed, the slumping problem, though the mound was being made. These days, researcher are stunned how native engineers built Monk’s Mound, and their findings concludes, that the massive earthwork may have been built surprisingly fast, may be in just a fraction of the time that archaeologists once thought. Monks Mound is an extremely complex bit of earthen architecture; with certainly in tune with their materials.
The original concept was much smaller mound; however several types of earth and clay from different sources had been used successively. Construction of Monks suggests that the stability of the mound was improved by the incorporation of bulwarks, some made of clay, others flood-plain, which allowed steeper slopes than the use of earth alone. Moreover, the structure rises in four terraces containing 22 million cubic feet of adobe, carried basket to the site. So, in brief, it took a lot of smarts to build Monks Mound and have it last for as long as it has.