Unguja (also referred to as Zanzibar Island or simply Zanzibar, in Ancient GreekMenuthias, Μενουθιάς - as mentioned in The Periplus of the Erythraean Sea, in Greek: Περίπλους τὴς Ἐρυθράς Θαλάσσης -) is the largest and most populated island of the Zanzibar archipelago, in Tanzania.