Ardahan Fortress was also called Kajats Fortress. It is located on a high and inaccessible rock and it has existed since ancient times. In the 9th century it passed to Bagratuni. The latter were redone, the fortress was further strengthened. In the 11th century, the Ardahan fortress was captured by Georgian troops. In 1236, the Mongols captured the fortress. In 1266, the fortress passed to the Georgian authorities of Samtskhe–Saatabago. At the beginning of the XV century, the Ardahan fortress was conquered by the Sultan of the Ottoman Empire Suleiman I (1402-1410). In 1555 it became the center of Ardahan province.

On August 22, 1828, Russian troops captured the Ardahan fortress and it was destroyed. On September 2, 1829 , according to the Adrianople Peace Treaty, the Ardahan fortress was again returned to Turkey. In the spring of 1919, Ardahan was liberated and passed to the Republic of Armenia on the territory of Western Armenia. In early November 1920, it was captured by Turkish troops led by Kazim Karabekir Pasha.