Gevhernik Castle, locally known as Gevhernik Kale or Ardanuç Kalesi, lies on a rock above the town of Ardanuç, in the province of Artvin in Turkey.
Gevhernik Castle was probably built in the 5th century by Vakhtang I, King of Caucasian Iberia (an ancient country in present-day Georgia and Turkey). In 744 the castle was besieged by the Ummayad Caliph Marwan II. Later that century it was restored by the Georgian Bagratid King Ashot I.
In 1080 hostilities started between the Bagratids and the Anatolian Turkish beyliks (small Turkish principalities governed by Lords called Beys) but being a mountain stronghold, Ardanuç was hard to conquer.
In the 13th century however the castle fell to the Mongols during their wars with the Turks and Georgians. In 1551 Gevhernik Castle finally fell, after yet another siege, to the Ottoman Empire and was restored in 1562 by Sultan Suleiman the Magnificent.
At present Gevhernik Castle is freely accessible via a set of wooden and iron stairs on the north side of the castle rock. A nice castle although the ruins don't show much architectural detail.