The Pishon and the Gihon (2:13) cannot be identified with certainty. If the land of Havilah was in southeast Arabia or on the African coast, as some biblical data suggest (see 10:7; 25:18; 1 Samuel 15:7), then the Pishon was possibly the Nile River. The Jewish historian Josephus thought that Havilah and the Pishon were in India (Antiquities 1.1.3).
Two other ideas suggest the Pishon and Gihon might be:
rivers in the mountains of eastern Turkey, where the Tigris and Euphrates (Genesis 2:14) also flow, and
the marshy delta near the Persian Gulf.
Current geographical conditions make it impossible to prove any theory with certainty.