The 298m-long Pol-e Si-o-Seh was built by Allahverdi Khan, a favourite general of Shah Abbas I, between 1599 and 1602. It served as both bridge and dam, and is still used to hold water today. Until recently there were tea houses at either end of the bridge, both accessed through the larger arches underneath, though only the northern one remains.
Arguably the finest of Esfahan’s bridges, Pol-e Khaju was built by Shah Abbas II in about 1650. It also doubles as a dam, and has always been as much a meeting place as a bearer of traffic. A bridge is believed to have crossed the waters here since the time of Tamerlane.
Its 110m length has two levels of terraced arcades, the lower containing locks regulating water flow. If you look hard, you can still see original paintings and tiles, and the remains of stone seats built for Shah Abbas II to sit on and admire the views. In the centre, a pavilion was built exclusively for his pleasure.
Source: Lonely Planet