Monks Mound

archaeological site, Illinois, United States

Also known as: Monk’s Mound

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June 30, 2026

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Monks Mound is a significant archaeological site located in Illinois, United States, near Collinsville. It is part of the larger Cahokia Mounds complex, which was the most extensive urban center in prehistoric North America north of Mexico.1

Monks Mound itself is the largest prehistoric earthen structure in the Western Hemisphere. Built between 900 and 1200 CE, it stands 100 feet tall and covers more than 14 acres. It served as the seat of governance for the ancient city of Cahokia, which flourished for about four centuries and reached a population of up to 20,000 people. The site demonstrates sophisticated planning with administrative, ceremonial, and residential zones, and evidence of extensive trade networks. The Mississippian culture, to which Cahokia belonged, was characterized by intensive agriculture, particularly corn cultivation, and a settlement pattern of towns with pyramidal mounds surrounding a central plaza.12

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Stone Age
Mississippian culture
…largest of the Mississippian earthworks, Monk’s Mound near Cahokia, Illinois, which measures 1,000 feet (305 meters) in length, more than 700 feet (213 meters) in width, and is still 100 feet (30.5 meters) in height. The first European explorers in the southern Mississippi Valley in the early 16th century found…
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…largest of the Mississippian earthworks, Monk’s Mound near Cahokia, Illinois, which measures 1,000 feet (305 meters) in length, more than 700 feet (213 meters) in width, and is still 100 feet (30.5 meters) in height. The first European explorers in the southern Mississippi Valley in the early 16th century found…
Read More

Cahokia Mounds
…immense earthworks, including the pyramidal Monks Mound (built between 900 and 1200), the largest prehistoric earthen structure in the Western Hemisphere, which rises to 100 feet (30 meters), covers more than 14 acres (6 hectares), and contains more than 25 million cubic feet (700,000 cubic meters) of earth. The seat…
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…immense earthworks, including the pyramidal Monks Mound (built between 900 and 1200), the largest prehistoric earthen structure in the Western Hemisphere, which rises to 100 feet (30 meters), covers more than 14 acres (6 hectares), and contains more than 25 million cubic feet (700,000 cubic meters) of earth. The seat…
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Mississippian culture
…the largest of the earthworks, Monks Mound, in the Cahokia Mounds near Collinsville, Illinois, which is approximately 1,000 feet (300 metres) long, 700 feet (200 metres) wide, and 100 feet (30 metres) high. The magnitude of such public works and the distribution of temples suggest a dominant religious cult and…
Read More
…the largest of the earthworks, Monks Mound, in the Cahokia Mounds near Collinsville, Illinois, which is approximately 1,000 feet (300 metres) long, 700 feet (200 metres) wide, and 100 feet (30 metres) high. The magnitude of such public works and the distribution of temples suggest a dominant religious cult and…
Read More