Keep in Mind that Jerusalem sits just west of the Great Rift valley. It is quite possible that legendary river of Eden originated from a massive artesian aquifer, the source of which has long since been disrupted by block faulting along the Rift. We know for a scientific fact that there is a considerable amount of "fossil" water under the Middle east in the deep-rock sandstone aquifers of the region such as the Nubian sandstone aquifers and equivalent formations.
Recall that in the days of Adam and Eve, a "mist" went up and watered the face of the Earth within the Garden (Genesis 2:6). Fountains of waters (underground waters under pressure gushing upwards) would certainly be a logical source for the generation of such a mist and would be a logical feed-source for such a river. Certainly, we cannot exclude this possibility.
In summary, although the modern-day geology and topography of the Middle-East does not readily reveal the exact location of the Garden of Eden and the four rivers source, guidance by faith from the Holy Bible and a forensic study of the region's geology reveals the matter. The available data appears to suggest that present-day Israel was the central location of the Garden of Eden.
See also
Oldest Human remains found in Israel!!!!