Hezekiah's Tunnel (Hebrew: Nikbat HaShiloah) - on assignment for City of David, Jerusalem, January 9, 2014.
The tunnel, which was discovered in 1838 by American biblical scholar Edward Robinson, bears the name of King Hezekiah of Judah, who ordered its construction in 701 BCE, as an aqueduct to provide Jerusalem with water during an impending siege by the Assyrian army, and also in order to cut off the water supply to the invading army.
The curving tunnel is 533 meters long, and by maintaining a precise 0.6% gradient altitude difference between each end, it conveyed water along its length from the Gihon Spring to the Pool of Siloam.
The Siloam inscription, a passage of inscribed text found in the tunnel during the late 19th century BC, commemorates the point where two teams, digging from each end, finally met in the middle
The tunnel can be walked through today from end to end in knee-high water.