I don't know if this is the true answer but there had been research done into an area called The Eye of Africa, it has seemed the most likely to me. Due geographical changes where its at would have been next to the ocean when it was at its peak. There has been many artifacts found right around and in this area but there hasn't been the ability to really excavate the area due to the difficulty of it's remote and less than safe location.
Hail Satan!