Alma Doshan fortress is located in a single, cylindrical mountain ridge. The surface of this mountain is relatively flat. The north-south length of the castle is about 500 meters and its east-west width is more than 100 meters. The remains of the architecture and the debris and masses of ballasts are on the surface of this mountain. On the Southern part of the mountain, near its abyssal edge there are remains of a large rectangular structure that seems to be the most important building of this castle. The name of this huge castle originates from the village of Alma Doshan. This military fortress is belonged to the Parthian period to Islamic Middle Ages of the 6th and 7th centuries AH.