Gihon Spring
The Bible says that King Hezekiah (c. 8th century BC), fearful that the Assyrians would lay siege to the city, blocked the spring's water outside the city and diverted it through a channel into the then Pool of Siloam. However, it is now known (as of 1997) that the earlier Warren's shaft system had already heavily fortified the Gihon Spring; Warren's shaft is not an aqueduct, and requires those desiring water to travel up and down it themselves—an arrangement that Hezekiah seemingly must have considered inadequate.