I am quite sure that it's a replica. The original coin is a tetradrachm from Lysimachus, king of Thrace, a general of Alexander the Great. In reverse we can see the head of Alexander the Great, wearing the horn of Ammon Zeus. In the obverse side, godess Athena, sitted, holding Nike (Victory), the inscription ΒΑΣΙΛΕΩΣ ΛΥΣΙΜΑΧΟΥ (King Lysimachus). This pattern is from Lampsacus mint (ancient Greek city in Asia Minor, nowadays Lapseki, Turkey).
