The Khaju (royal) bridge is one of the masterpieces of Isfahani renessaince architecture. It was built across the Zayandeh-rud river under the reign of Shah Abbas II in 1650 on the foundations of an older bridge. It has 23 arches and is 105 metres long and 14 metres wide. The Khaju bridge acts as a weir, keeping the water levels of the river high even during the dry summer months.