Gadara Aqueduct

The Gadara Aqueduct was a Roman aqueduct to supply water to the city of Gadara, modern-day Jordan, and the longest known tunnel of antiquity. The 170-kilometre-long (105.6 mi) pipeline was constructed in the qanat technology, that is as a series of well-like vertical shafts, which were connected underground from opposite sides by gently sloping tunnels. The longest section featured a length of 94 km (58.4 mi). Partly following the course of an older Hellenistic aqueduct, excavation work arguably started after a visit of emperor Hadrian in 129–130 AD. The Gadara Aqueduct was never quite finished, and was put in service only in sections. It was discovered and explored as late as 2004.

Map of Gadara Aqueduct, Jordan