Workers building a sewer line in Jerusalem unearthed a section of the ancient lower aqueduct, which had long been one of the city's principal sources of water.
Constructed by the Hasmonean kings more than 2,000 years ago to provide clean water to Jerusalem, the aqueduct was part of an elaborate water supply system devised for a city that had experienced a number of droughts.
The water conduit functioned intermittently until about 100 years ago, when it was replaced by a modern electrically operated system.
Video: Ancient Roman Aqueduct Source Discovered
Unearthed in Umm Tuba, an Arab neighborhood in East Jerusalem, the aqueduct begins at the Eitam spring near Solomon's Pools, three reservoirs south of Bethlehem that are the heart of the water system, and is approximately 13 miles long.
"Despite its length, it flows along a very gentle downward slope whereby the water level falls just one meter (3.2 feet) per kilometer of distance (0.62 miles)," Ya'akov Billig, the excavation director, said.
"At first, the water was conveyed inside an open channel and about 500 years ago, during the Ottoman period, a terracotta pipe was installed inside the channel in order to better protect the water," he added.
Medieval Aqueduct Found in Jerusalem
The aqueduct tunneled beneath the town of Bethlehem, ran through a number of neighborhoods in Jerusalem and finally entered the Temple Mound over Wilson's Arch bridge.
The Umm Tuba section of the aqueduct has now being covered up again "for the sake of future generations," the Israel Antiquities Authority (IAA) said.
The archaeologists are now working to expose sections of its remains and make them soon accessible to the general public.