It is a 28-meter wall which is the remnants of Tabriz city citadel and city wall. Ark construction was aimed to make a big mosque in the 13th century; however, the construction was never completed and a devastating earthquake ruined much of it except the main wall of the mihrab, which is still standing today. In later years this wall used as part of the city wall and the main part of fortress of Tabriz until end of Qdjar dynasty. During the wars of Safavid-Ottoman, and Perso-Russian wars this fortress was always one of the major Strong holds of Iranian troops. In early 20th century the constitutional revolutionists used the ark citadel as their military base in Tabriz. At the collapse of Autonomous Government of Azerbaijan Ark was the latest resistance of their troops against Iranian army. The surrounding area of Ark has been used to build another big mosque for Friday prayers.