Bab Qinnasrin was originally built by the Hamdanid ruler of Aleppo Sayf al-Dawla but was completely rebuilt in 1256 by Al-Nasir Yusuf II who renewed the southwestern part of the city wall between the Qinnasrin and Antakiyya gates. The architecture of Bab Qinnasrin was formed by two massive towers of unequal heights. The western tower, eighteen meters high, was used for defense while the eastern one, twenty-six meters high, formed the entrance. The Ayyubid portal in the form of a tall arch leads to a tripartite hall with a cross vaulted middle chamber. The chamber opens into another cross-vaulted chamber that is connected to the western side of the gate by a corridor that extends to the wall behind the western tower. Passing through two more chambers, one enters the city. The plan's sequence of rooms form an enclosed square with an open court in the middle that has a water well, cisterns, and flour and oil mills. The gate also holds the Shrine of Khalil al-Tayyar. The western side has been completely demolished.
The innovative plan establishes this structure as a fortress comparable to the Citadel Gate.
Tabbaa, Yasser. Constructions of Power and Piety in Medieval Aleppo. University Park, PA: The Pennsylvania State University Press, 1997.