The author challenges the opinion that the «Periplus of the Erythraean Sea» was based purely on the personal experience of its author, who is normally supposed to have been a sea-trader or a ship-owner. The article is focused on the description of Nabataea in the «Periplus». Consideration of the previous Classical tradition on Nabataea, in particular the description of the port Leuke Kome and the way from it to Petra in the works of Hieronymos of Kardia, Agatharchides and report of Aelius Gallus’ campaign in Arabia retold by Strabo and Diodorus of Sicily enable us in general to suppose that the author of the «Periplus» in his description of Nabataea referred to the information contained in these sources and had most probably never been on the North Arabian shore of the modern Red Sea and in particular that the restoration αναβαταιων > ἀνάβασις in the § 19 of the «Periplus» for designation of the road «through» Leuke Kome to Petra is the only possible one. This fragment of the «Periplus» seems to go back to the information on the sea- branch of the «Incense Road».