the distance between every channel and the ceiling base is 21 meters. There are several sluice gates under the archways, through which the water flow of the Zayanderud is regulated. When the sluice gates are closed, the water level behind the bridge is raised to facilitate the irrigation of the many gardens along the river upstream of the bridge. On the upper level of the bridge, the main central aisle was utilized by horses and carts and the vaulted paths on either side by pedestrians. Octagonal pavilions in the center of the bridge on both the down and the upstream sides provide vantage points for the remarkable views. The lower level of the bridge may be accessed by pedestrians and remains a popular shady place for relaxing. Iranian architects have raised concerns about damage inflicted on the bridge during recent "improvement program" renovations, citing, among other problems, the destruction of the original stepped base of the bridge, the alterations made to the riverbed, and the removal of the Safavid inscribed stone blocks from the bridge. Gallery See also Si-o-se-pol, another such bridge on the same river Putra Bridge, a bridge in Malaysia that was inspired by Khaju References Further reading External links Tourist attractions in Isfahan Bridges in Isfahan Bridges in Iran Bridges completed in the 17th century Buildings and structures completed in 1650 1650 establishments in Iran Safavid architecture