Later King Hezekiah devised a system to prevent David’s feat from being turned against the Jews: he built a tunnel to bring the Gihon waters into the city walls and store them in a pool, hiding the entrance of the spring and keeping invaders such as the Assyrians from finding water as they camped outside the wall. According to the biblical account, laborers in Jerusalem dug from opposite ends of the tunnel in order to save time as the Assyrian army approached. Minutes before the enemy’s arrival, the laborers heard the picks and voices of their companions on the other side just a few meters off the mark (II Chronicles 32). In 1880, a few years after the tunnel was excavated, a local boy discovered an inscription carved by Hezekiah’s engineers. The Siloa inscription describes the tense but jubilant moment when the construction crews completed the tunnel. (The original inscription is in Istanbul, but a copy is on display at the Israel Museum.)

You can slosh through Hezekiah’s Tunnel with a flashlight or a candle, though it is not advisable to do so without a guide. The water is about lm high, and wading the 0.5km takes about 30 minutes. You’ll get wet. Start at the Gihon Spring source on Shiloah Way, which branches to the right from Jericho Rd. as you approach the Kidron Valley from the bottom of the Mount of Olives. Steps from the City of David excavations also lead down to the Gihon Spring. The tunnel ends at the Pool of Shiloah (Silwan in Arabic, Siloam in Hebrew). You can then walk back to the road to your left and catch an Arab bus up the valley. (Open all day. Free, although several little boys will try to convince you otherwise.)

Several organizations offer tours; check at the tourist office for schedules. Recent years have witnessed increasing tension in this much disputed area. Orthodox Jewish nationalists have attempted to establish a Jewish presence in the midst of Arab Silwan; Arab homes were quietly purchased and their residents evicted in a dramatic, middle-of-the-night maneuver. A Jewish bastion, guarded by barbed wire, is perched precariously and conspicuously in the center of this entirely Arab neighborhood; innocent tourists may find themselves walking into a potentially dangerous situation. As always, read newspapers and consult tourists offices before exploring.