Hezekiah's Tunnel as
you can visit today

In 1838, biblical scholar Edward Robinson discovered a tunnel that connected the Gihon Spring, outside of Jerusalem's walls to the Siloam Pool within its walls. The tunnel was cut out through bedrock, S - shaped with a length of 1,750 feet (1/3 of a mile), and with a slope of 0.6% which brought fresh water to inhabitants within the walls of Jerusalem.

Three biblical references explain the purpose and reason for the tunnel:

Now the rest of the acts of Hezekiah and all his might, and how he made the pool and the conduit and brought water into the city, are they not written in the Book of the Chronicles of the Kings of Judah? (2 Kings 20:20)

Now when Hezekiah saw that Sennacherib had come and that he intended to make war on Jerusalem, he decided with his officers and his warriors to cut off the supply of water from the springs which were outside the city, and they helped him. So many people assembled and stopped up all the springs and the stream which flowed through the region, saying, "Why should the kings of Assyria come and find abundant water?" (2 Chron 32:2-4)

It was Hezekiah who stopped the upper outlet of the waters of Gihon and directed them to the west side of the city of David. And Hezekiah prospered in all that he did. (2 Chron 32:30)

Jerusalem was vulnerable to any attacking force who could block and control its water supply. In preparation for the impending siege by Sennacherib and the Assyrians (2 Kings 18:1-37; 19:1-37), King Hezekiah (reign approximately 725 B.C. – 696 B.C.) ordered for the construction of the aqueduct which was chiseled out by 701 B.C.

The Siloam Inscription

Unbeknownst to Edward Robinson and discovered later in 1880 inside Hezekiah's Tunnel, the aqueduct's completion was commemorated by its builders with an inscription called the Siloam Inscription. Now housed at the Istanbul Archeology Museum, the inscription is comprised of six lines and is noteworthy as one of the oldest examples of Hebrew written in the Paleo-Hebrew alphabet. The plaster used for the Siloam Inscription and the organic matter contained within it was dated to the 8th century B.C. which is coincident with the time of Hezekiah.

While it is not completely legible, the Siloam Inscription describes how the tunnel was evacuated by two teams starting at opposite ends. Led by sounds generated by hammering from above, stonecutters were guided to each other and met at the center all the while mindful of the distance to the top of the rock. Despite having several directional errors and misalignment of the tunnel center, the stonecutters succeeded in completing the tunnel before the siege.

The biblical record of Hezekiah's Tunnel is remarkably accurate. Not only does the tunnel exist and constructed at the appropriate time, but its location and flow direction is also correct: west of the City of David and flows from east to west (2 Chron 32:30).

Extrabiblical records confirm the biblical record. In 1830, a six sided clay artifact in Nineveh was discovered, which became known as the Prism of Sennacherib (housed at the British Museum and dated at 691 B.C.). Comprised of six columns with over 500 lines of writing in Akkadian cuneiform, it records the first eight military campaigns of king Sennacherib who reigned during 701-681 B.C. Of particular interest regarding the Bible is the translation about the conquest of Judah:

"As to Hezekiah, the Jew, he did not submit to my yoke, I laid siege to 46 of his strong cities, walled forts and to the countless small villages in their vicinity, and conquered (them) by means of well-stamped (earth) ramps, and battering-rams brought (thus) near (to the walls) (combined with) the attack by foot soldiers, (using) mines, breeches as well as sapper work. I drove out (of them) 200, 150 people, young and old, male and female, horses, mules, donkeys, camels, big and small cattle beyond counting, and considered (them) booty. Himself I made a prisoner in Jerusalem, his royal residence, like a bird in a cage. I surrounded him with earthwork in order to molest those who were leaving his city's gate".

A wall relief showing the
sloped ramps attacking Lachish

The Bible records Sennacherib entering Judah (2 Chron 32:1), besieging Lachish (2 Chron 32:9) and after its conquest, proceeding to attack Jerusalem (2 Kings 18:13 - 19:37; Isa 36:1-22).

An impressive wall relief among the ruins of Nineveh portrays the conquest of Sennacherib. Pictures of the sloping siege ramps against the city of Lachish, Assyrian warriors and Jewish captive celebrate the victory over Lachish. However there is not one image that celebrates the conquest of Jerusalem.

The Bible records Hezekiah as seeking the help of the prophet Isaiah (Isa 37:1-13) and praying to God for deliverance (Isa 37:14-20). God responds though the prophet Isaiah (Isa 37:21-35), Jerusalem does not fall, and the Assyrians are destroyed (2 Chron 32:20-22; Isa 37:36-37).

Assyrian records indicate that after Sennacherib returned home, he was murdered by his sons. The Bible records this as well in Isaiah 37:37-38.

Update 2025: The dates assigned the Siloam Inscription and Siloam / Hezekiah's Tunnel are questioned.

Excavating the numerous and crisscrossing water tunnels that make up the water system arising from the Spring of Gihon, archaeologists Ronny Reich and Eli Shukron observed that at the Rock-cut Pool connection of Tunnel IV, there was a smoothed place for a plaque very similar to the smoothed area for the Siloam Inscription.

They believe that this marked the beginning of the Siloam / Hezekiah's Tunnel just as the Siloam Inscription marked its end. While Tunnel IV connects the Gihon Spring to the Rock-cut Pool, they conclude that that the Siloam / Hezekiah's Tunnel begins at Tunnel IV.

Image from:
Jerusalem's water systems

In the Round Chamber, blocking the entrance of Tunnel IV, they found rubble upon which a house was built.

Pottery shards found in the debris just beneath the house dated the rubble and house to the late ninth – early eighth century B.C., predating Hezekiah by almost one hundred years.

If Tunnel IV and the Siloam / Hezekiah's Tunnel had not be built, water would have continued to flow into the Rock-cut Pool, and the house would have been underwater.

This additional data strengthened the view that the Siloam / Hezekiah's Tunnel was constructed by a predecessor possibly as early a King Jehoash (835-801 B.C.)

As the result of their extensive study of Jerusalem's water systems, Reich and Shukron believe that water from the Spring of Gihon was managed by two Canaanite built water systems:

Channel II carried water south along the Kindron Valley.

Tunnel III, carved into the northeast corner of the Rock-cut Pool's floor, carried water to the deep Round Chamber.

Later, as the City of David was growing, the Israelites built a sequence of water tunnels in a manner to avoid the flow of water from interfering with construction.

Tunnel IV, starting in the Round Chamber and heading northwest, would become the Siloam / Hezekiah's Tunnel. After completion of the Siloam / Hezekiah's Tunnel, the construction of Tunnel VI began.

Tunnel VI, starting as an offshoot of Tunnel IV, went eastward until it connected to the Gihon Spring.

By connecting the Gihon Spring to the Pool of Siloam via the Siloam / Hezekiah's Tunnel, water ceased to flow through the Canaanite constructed Channel II and Tunnell III depriving water to the Rock-cut Pool / Round Chamber.

These recent archaeological findings suggest that the Siloam / Hezekiah's Tunnel may have been largely built or in part by the time of Hezekiah's reign. Without additional data, it is difficult to ascertain what Hezekiah's contribution was to the construction of Jerusalem's water tunnel system. Nevertheless, the biblical record is clear that in preparation of Sennacherib's siege of Jerusalem, Hezekiah's tunnel work contributed to the success of surviving the siege.