The Olbian Territory is located between the Kalykadnos river and the Lamos river in Rough Cilicia. In the early 2nd century B.C., an extensive construction period began in the Olbian Territory. These construction activities were carried out by the local dynasty, supported by the Seleucid kingdom in order to protect and secure their western borders after the Apameia treaty. A common caracteristic of the structures in these settlements is the extensive usage of the polygonal masonry, particularly in the defence structures. Another common feature of these settlements is their strategical position on which these settlements were found. It is a fact that all these settlements were established at the edges of deep valleys that provided the communication between the inland and the coastal regions. While their spesific locations enabled these settlements to control and defend these important routes, their naturally protected positions made their own defence easier as well. Finally, all of these settlements had necropolis areas in their neighbourhoods. This territorial defensive network of the settlements was not a unique example in that period. On the contrary, this type of territorial defence networks were employed in some regions in the Hellenistic world since the 5th century B.C. In this article it is aimed to determine the characteristic of the urbanization in the territory in order to find out whether the factors that affect this urbanization process are external or internal in the Olbian Territory during the Hellenistic period.