In his Natural History (Book 6.32.149-152), completed by 77 AD, the Roman writer Pliny the Elder describes the southern coast of the Arabian Gulf. Among its principal towns and markets he mentions 'the town of Omana which previous writers have made out to be a famous port of Carmania', i.e. Kerman, the southeastern province of Iran. The approximately contemporary Periplus of the Erythraean Sea, we read that, 'Sailing through the mouth of the Gulf, after a six-days' course, there is another market town of Persia called Ommana'. Omana also appears as a town in the vicinity of the Eualenoi, i.e. the inhabitants of Awal or Bahrain as it was known in some late sources, in the Ethnika of Stephen of Byzantium, written around 530 AD
The absence of a sizable archaeological site of the first century AD on the coast of Kerman, coupled with Plinys admonition that 'previous writers' had mistakenly assigned this Arabian placename to the coast of Iran, have led some scholars to look for Omana on the Arabian coast of the lower Gulf. In this area there is no other site which comes close to the size of al-Dur, nor is there any other site at which so much material - Roman glass, pottery, coinage, Namord ware, etc - has been found which dates precisely to the time of Pliny's account. The pairing of Apologos in Characene with Omana, and the discovery of coins of the kingdom of Characene at al-Dur, provides yet another argument in favour of the identification of al-Dur with ancient Omana.