This is the entrance to the Khan As’ad Pasha, built in 1749 (the Bradt guide has 1751-1753) by a governor of Damascus, a member of the wealthy Azem family. It is located at the far end of the Spice Market, the souk that runs south from the open place in front of the Azem palace to the Straight Street. I found the khan had closed but since the gate is the main sight I enjoyed myself greatly. In front are wonderful lamps (you see them elsewhere too) made of glass discs that are joined hanging from the ceiling of the souk. I understand the khan is often closed, it used to house the Natural History Museum for a while.