2 Chronicles 32:3

32:3-5 Sennacherib’s attack did not come as a surprise; Hezekiah provoked it by breaking a treaty (2 Kgs 18:7, 20). Because water was critical to both attacker and defender in siege warfare, Hezekiah made sure that Sennacherib’s army would not have access to the city’s water supply. In one of the most famous engineering feats of ancient times, Hezekiah’s tunnel connected the fresh waters of the Gihon Spring to the pool of Siloam, making water accessible from within the city walls. This famous tunnel is almost one-third of a mile long (approximately 580 yards [530 meters]) and about six feet [2 meters] high. The famous Hezekiah inscription, discovered in the tunnel in 1880, describes how the excavators met to join the two ends. Although much of the tunnel consisted of natural underground aqueducts, it was a tremendous strategy for protecting the citizens of the city.