River in the Garden of Eden

Gen 2:10..14
And a river went out of Eden to water the garden; and from thence it was parted, and became into four heads.
The name of the first is Pison: that is it which compasseth the whole land of Havilah, where there is gold;
And the gold of that land is good: there is bdellium and the onyx stone.
And the name of the second river is Gihon: the same is it that compasseth the whole land of Ethiopia.
And the name of the third river is Hiddekel: that is it which goeth toward the east of Assyria. And the fourth river is Euphrates.