Welp, it flowed in completely the opposite fucking direction to the one on this map, which makes a lot more geographic sense, so don't really think Herodotus gets any points on this one

It's very short but cool

But you don't need to know about that river to look at a map and go "So there was an ancient river that flowed uphill?"

Tamanrasset River - https://en.wikipedia.org/wiki/Tamanrasset_River