The largest of several intact sections of the Roman aqueduct serving Nemausus (Nimes) may be seen at Pont du Gard, 18km NE of Nimes. The famous three-tiered aqueduct-bridge, of Roman engineering feature, was built of limestone blocks weighing up to six tons each, fitted together without mortar and secured with iron clamps. It spans 275 meters over the Gardon valley. The aqueduct brought water 50 km from the springs of Fontaine d'Eure at Uzes to Nimes down a total gradiant of only 17 meters.
The lowest of the Pont du Gard's three tiers is 142 m in length and contains six arches 22 m high. The middle tier has eleven arches each 20 m high, spanning 242 m. The third and topmost row of 35 arches (seven m high) covers 275 m and carries the all-important water channel.