Qantaret Harba is a bridge located in the vicinity of Balad's rail station, a city ninety kilometers north of Baghdad. It lies on the main road linking Baghdad to Samarra and Tikrit. The bridge was name after the town of Harba that lies to its southwest. It was built in 1228 in the beginning of the caliph al-Mustansir's reign as part of the irrigation project implemented to provide the neighboring town and villages with water after a sudden change of the Tigris river course. It bridges the Dujail canal.
The bridge is built with burnt bricks and toped by the same material laid in a fish scale pattern. It is supported on four arches alternating three niches measuring 1.5 meters each. The two side arches measure 5.5 meters while the central ones measure 5.8 meters. Overall, the bridge spans 54 meters in length and has a width of 11.8 meters. Three of the arches are now buried in earth up as high as their springer while one of the two central ones remains uncovered and constitutes a route for the waters of the Dujail Canal flowing occasionally.
The bridge is mostly known for its inscription running above the arches to a length of one hundred meters on each side. It is built out of small inserted brick pieces in the ala gaza technique, meaning edgewise, where edges project enough from the frieze surface.
This technique of cutting and hewing bricks is very different from the traditional carving method. The inscription is laid on a background similarly composed of pieces decorated with geometrical patterns and is framed from above and below with three bands of burnt bricks cut in the same technique.
The inscription content praises al-Mustansir for his irrigations works, and for the bridge that connected the two banks.
Directorate of Antiquities. 1935. Harba Bridge, Baghdad. Printed at the Government Press.
Michell, George, Ed: 1978. Architecture of the Islamic World. London, Thames and Hudson, 251.
Al-Janab Tariq Jawad, 1982, Studies in Medieval Iraqi Architecture, Baghdad, Ministry of culture and Information, State Organization of Antiquities and Heritage, 224-225.