If you graduated U.S. Public School education system(k-12), you might have learned about the 4 great River Valley Civilizations: Indus, HuangHe, Nile, Euphrates. They were basically the birthing ground for Modern Eurasian and African (and American) history.
There are a lot of other river valleys in the world and I was wondering if anyone here knows a thing or 2 about them. If you do, can you provide any articles (or internet links) that has evidence indicating the existence of other Early River Valley Civilizations.
--Also is this a question I can ask on this Stack Exchange? Thanks in advance.