Monks Mound: Largest pyramid by footprint, sod construction and flooding preservation. Monks Mound has the largest base footprint of any pyramid in the world, larger than the Great Pyramid of Egypt It was built using inverted sod block construction, the same technique used in European barrows and burial mounds A directional drill hit a stone core in the mound in the 1870s-1910s while installing drainage - the drill bit remains embedded in the mound today
Monks Mound at Cahokia has a base footprint roughly the same size as the Great Pyramid of Giza — with a larger perimeter (13.1 acres / 5.3 hectares). Built with non-local soil, likely transported by canoe or raft since the site sits on an alluvial flood plain. A drill bit is reportedly embedded inside.
Key Facts
- Monks Mound has the largest base footprint of any pyramid in the world, larger than the Great Pyramid of Egypt
- It was built using inverted sod block construction, the same technique used in European barrows and burial mounds
- A directional drill hit a stone core in the mound in the 1870s-1910s while installing drainage - the drill bit remains embedded in the mound today
- Mound soil was intentionally non-local, brought in by canoe or raft from elsewhere since the site sits on an alluvial flood plain
- The mound was intentionally designed to be flooded for preservation - anaerobic conditions protect it better than air
- Buildings were constructed on top of the mound, including a 100 ft by 80 ft structure with cedar posts
- Most mounds in St. Louis were destroyed for railroad fill except one; hundreds were destroyed in the 1870s-1910s
Related site: Cahokia Mounds State Historic Site — view location, images, and history on the Ancient Nerds map.
Source: The Roundtable Chronicles by Institute for Natural Philosophy