What geographic conditions posed the greatest challenge for early civilizations?
(this is about civilizations like the olmec the aztec the incas and indian tribes in north america)
example 1:
example 2:

The civilizations you mention are not that early compared to most. But any civilization needs to have a secure food supply. So a geography that includes an area for good farming would be a necessity. Also, making sure the river you choose to live by is not going to dry up or freeze over every year. I hope that this is the answer that you were looking for and it has helped you.

B. John Locke

Explanation: