Monks Mound
Monks Mound at Cahokia · Mound 38
Mississippian 900–1200 CE (peak 1050–1200)·Mississippian (Cahokia)·🇺🇸 Illinois, United States
About
About Monks Mound
Largest earthen structure in the Americas north of Mexico and centerpiece of Cahokia Mounds State Historic Site. This four-terrace platform mound rises 30 m (100 ft) high, 291 m long and 236 m wide, containing ~22 million cubic feet of hand-carried basket-loaded fill, built in ~14 construction stages. Summit held a 15 m-long thatched elite building (15×32 m) evidenced by postholes; southern ramp/stair was astronomical causeway. Part of UNESCO World Heritage Cahokia Mounds (1982).
Why it mattersLargest pre-Columbian earthwork north of Mexico; type-site for Mississippian urbanism and ranked society before chiefdom-to-state debate.
Open questions
Mysteries & theories
Mysteries
- 01How labor mobilized without wheels or draft animals to move 22 million cu ft earth
- 02Why staged basket loads were of visibly different clays (symbolic stratigraphy?)
- 03Function of summit building – elite house vs temple
Theories
- 01Cosmogram model: terraces represent layered cosmos
- 02Competitive mound-building as status display; abandonment due to floodplain depletion and 1200 CE political shift
Theories are interpretations, not findings. The seal above tells you how much scholarly weight the place carries.
History
How it came to be
- Built
- c.900–1200 CE, main construction 1050–1100 CE
- Period
- Mississippian 900–1200 CE (peak 1050–1200)
- Culture
- Mississippian (Cahokia)
- Purpose
- Elite residence and temple platform, ceremonial center and cosmogram aligning cardinal directions
- Excavation
- Partially excavated
c.900–1200 CE, main construction 1050–1100 CE
Initial construction
c. 1405 CE
Abandonment
On the ground
Structures & features
38.6605° N · 90.0626° W · 157 m · 3 mapped features
Summit elite structure postholes
structure30×15 m thatched building footprint on fourth terrace
38.6606° N · 90.0624° WSouth ramp / stair causeway
causeway50 m long access ramp aligned to southern Woodhenge sunrise
38.6595° N · 90.0626° WFirst terrace borrow pits
quarryScalloped borrow areas west of mound
38.6602° N · 90.0635° W
Gallery