Few places better illustrate the layered history that archaeology uncovers than the little ridge known as the City of David, the oldest inhabited part of Jerusalem. For example, to tell the story of the Pool of Siloam, where Jesus cured the blind man, we must go back 700 years before that—to the time of the Assyrian monarch Sennacherib and his siege of Jerusalem.

Hezekiah, the Judahite king at that time, could see the Assyrian siege coming. Protective steps were clearly called for, especially to protect Jerusalem’s water supply. The only source of fresh water at this time was the Gihon Spring, near the floor of the adjacent Kidron Valley. So Hezekiah decided on a major engineering project—he would construct a tunnel under the ridge on which the City of David lay to bring the water of the spring to the other, less vulnerable, side of Jerusalem. It was dug by two teams of tunnelers working from opposite ends, meeting in the middle—it’s still a mystery how they managed to meet, but they did. A memorial plaque was carved in the tunnel wall to commemorate the feat—the famous Siloam Inscription, now in the Istanbul Museum (it was discovered in Ottoman times). Water flowed through the tunnel from the spring to the Pool of Siloam at the other end. It is still known as Hezekiah’s Tunnel, and it is still a thrill for tourists to walk through its 1750-foot length.