From www.itto.org:  The Bridge of Khaju or pole-i-Khaju, the
most famous of Isfahan bridges, has roused the admiration of
travelers since the 17th century. There was an earlier bridge
across the river at the same spot, near the district of Khaju on
the old Shiraz road; this was probably built in the reign of
Timurian sovereign, one of the successors of Tamerlane (15th
century). Shah Abbas II built the present structure round about
1650. It has 23 arch and are 436 feet long and 39 feet wide. It
is also 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 gardens. With its two
stories of arcades with intersecting arches, its stone steps
downstream with the water cascading over them, and its two large
pavilions in the center- (The Prince` Parlors)- this bridge is a
masterpiece of balance and harmony. The outer side of the
arcades is decorated with richly colored tiles, and the interior
of the pavilions w