Cahokia Mounds belongs to the Common Era — dated here to c. 1100 CE at Illinois, USA. Dates mark a scholarly centre of gravity (dedication, completion, or iconic phase), not a single foundation day.
Monks Mound — the largest pre-Columbian earthwork north of Mexico — once a city of ~20,000.
How it amazes the brain
Basket-load construction, woodhenges for calendars, and a planned plaza.
Why it counts as a wonder
It never needed a contest ballot to scramble the brain: scale, craft, or sheer improbability is enough.
A forgotten metropolis hiding in plain sight beside modern highways.
On dating
CE means years after the traditional birth of Christ. A monument listed as c. 1100 CE may have been founded earlier, rebuilt later, or become famous only in one phase. Engineering wonders (dams, tunnels, orbiting labs) are dated to opening or assembly.
This is story 63 of 100 in The Trend Ledger’s illustrated desk on world wonders raised after the birth of Christ — the companions to our BCE series.