Drift off to the forgotten story of America's original pyramid builders. The Mississippian culture built massive earthwork mounds across the eastern United States, with the city of Cahokia at its height rivaling the size of medieval London — and yet most Americans have never heard of them.

Covered: Origins of the Mississippian culture, the construction and purpose of the mounds, the city of Cahokia, religion and the Southeastern Ceremonial Complex, the mystery of Cahokia's collapse, related cultures like the Hopewell tradition, and why this civilization was largely erased from popular history.

✦ 2-hour deep dive ✦ Calming narration ✦ Native American and American history for sleep

Sleepless History is an educational sleep podcast covering ancient civilizations, lost cultures, and Native American history — made to help you fall asleep.