Approaching the Dome of the Rock terrace from the main gate of the Haram al-Sharif, Bab al-Silsila, one encounters wide stone steps crowned with the Southwest Qanatir, a triple-arched arcade that frames the view of the mountains surrounding the Old City of Jerusalem. The present steps and colonnade were built under the reign of Sultan Qaytbay to replace the narrow vaulted stairway with the unrespectable name "the Lane of Kissing" (zuqaq al-bus).

The southern pier leans on the northwest corner of the Qubbat al-Nahwiyya, built in 1207-8. The northern pier on the other hand was built substantially wider, since it had to support the lateral thrust from the arcades without the help of another structure. The building that abuts the northern pier today is a later Ottoman addition. The columns are in secondary use, apparently from Byzantine origin and are made of a variety of dissimilar components. The Qanatir is capped with a gabled roof on top of a cavetto cornice to shed rainwater.

Sources:

Burgoyne, Michael Hamilton. 1987. Mamluk Jerusalem: An Architectural Study. Jerusalem: British School of Archeology in Jerusalem, 570-571

Burgoyne, Michael H. 1976. A Chronological Index to the Muslim Monuments of Jerusalem. In The Architecture of Islamic Jerusalem. Jerusalem: The British School of Archaeology in Jerusalem.