Hezekiah’s Tunnel means in the bible: A complex engineering plan that extends approximately 1770 feet through limestone rocks, to bring the waters from Gihon spring within the walls of Jerusalem into the pool at Siloam. This tunnel was constructed in Hezekiah’s time, around 701 B.C. to defend against an attack by the Assyrian army, Sennacherib 2 Kgs. 20:20; 2 Chr. 32:4, 30. Both ends were dug by workmen in a zigzag pattern until they came to a meeting. An inscription in stone at the Siloam tunnel end tells the dramatic story of their meeting. The inscription reads, “The boring through has been completed. This is the tale of the boring through. The workmen continued to lift pick and pick. Each worker turned toward his neighbor while there were three cubits left to cut. However, one heard his neighbor’s voice calling his neighbor because of a crack in the rock to his right. The stonecutters were at work, so each man went to his neighbor, picked to pick.
(in Bible Dictionary)