Following on from the Great Pyramid of Cholula, here’s another mysterious ancient city, Cahokia.

“A lot of the world is still relating in terms of cowboys and Indians, and feathers and teepees,” says Thomas Emerson, professor of anthropology at the University of Illinois. “But in AD1000, from the beginning, [a city is] laid on a specific plan. It doesn’t grow into a plan, it starts as a plan. And they created the most massive earthen mound in North America. Where does that come from?”

One major difference between Cahokia and Cholula is that Cahokia is not mostly hidden under jungle vegetation in what is now Mexico – it is just eight miles from St. Louis in the state of Illinois, USA.