Found downstream from the Allahverdi Khan Bridge, it is the most beautiful historical bridge in Esfahan. It is believed that its name is derived from khajeh ("a courtier" or "a noble"), and thus the bridge is named after a neighboring district, inhabited by the court elite. However, in various periods it was also known as the Royal, the Zoroastrian, the Hasan Abad, or the Baba Rokn al- Din Bridge.
It is a magnificent structure, measuring 132 m long and 12 m wide. It consists of two decks; the upper deck functions as a passageway, while the lower deck constituted the recreation area.
The original construction probably took place during the reign of the Timurid sovereign, Hasan Beik, one of Tamerlane's governors in the 15th century. However, the present structure is a restoration of the 1650s, dating from the rule of Shah Abbas II. The bridge was repaired in 1873, as its inscription suggests.
The bridge also acted as a dam; sluice gates between the piers closed the canals, raising the water level upstream so that large reserves could be collected for irrigating the surrounding fields and gardens. There are 21 sluices at the lower part of the bridge, ranging in width from 2.6 to 3.9 m. The river flooded to form a large lake on the west side of the bridge, in front of the royal palaces.
During the Safavid period, the court and its nobles gathered there to watch spectacular pyrotechnic shows and water competitions. In the midsummer of each year, the festival of Ab-pashan ("water splashing") was held in the vicinity of the Khaju Bridge. Both the rich and the poor gathered along the river banks and splashed water on each other in belief that it will purify them from illness and harm.
Water also served more prosaic, but not less important service, washing away excesses of lime from the soil, and making it suitable for cultivating the renowned melons of Esfahan. The dam is still used to raise the level of the river sufficiently to fill irrigation canals (madi) on either side of the river.
The Khaju Bridge has aroused the admiration of travelers since the 17th century. Its tiered recesses, arcades and galleries, stone steps with the water cascading over them, splendid tile work of the arches of the upper booths and lower spans have made the Khaju Bridge outstanding among all the bridges in Esfahan. Some of its most fascinating features are the pavilions called "Princes' Parlors" lavishly decorated on the exterior with brightly colored faience, while their interior is adorned with mural paintings and plaster work. Two sets of spiral stairways lead to the alcoves. It is worth noting that in addition to their aesthetic function, the pavilions also structurally increased the stability of the bridge.