Erzurum is the largest city in the Eastern Anatolia Region in terms of geographical size. In this region there are large rivers emerging from Erzurum and it's surrounding area. One of the most important of these rivers, without a doubt, is the Aras River. From the ancient times great civilizations founded and flourished on and around Aras River. Ancient writers Herodotus and Xenophon made references to this river. Natural paths farmed by Aras have been very effective in every period of the history in martial, commercial, cultural and political developments between Iran and Caucasia. In 1st millennium BC Diauehi Kingdom's presence can be seen in the region. In the 1st Millennium BC Urartians became an important power in and around Van. In order to exert control on Diauehi Kingdom the launched military campaigns on Erzurum and it's surrounding area. We can identify these expeditions from the inscriptions which are important for the regional history such as Hasankale (Pasinler), Yazılıtaş, Delibaba, Süngütaşı (Zivin) and Avnik (Güzelhisar). Avnik Fortress which stood on a location was used by Urartians in order to control the important routes. Stoneware data shows that there had been a settlement since Bronze Age. It is one of the most important fortresses besides the Pasinler Fortress. Avnik Fortress which maintained its importance trough time is one of the best fortified locations of the Middle Ages.İ