Genesis identifies four rivers that went out of Eden, Pishon,
Gihon, Tigris and Euphrates. Only the last two of which are
clearly known to us, but the Gihon is described as being in
Ethiopia, which is actually in another continent.
Leon Kass (The beginning of wisdom) says that there can
be no single terrestrial place that would serve as the common
source of these four widely separated rivers.
True, the Tigris and Euphrates do meet, but the lands the
text associates with the first two rivers are clearly separated
from the Tigris, Euphrates valley, the first to the north, the
second to the south.
This geographical impossibility tells us that the Garden of
Eden was a purely mythical place.