Sandu Mendrea/Israel Antiquities Authority

The waters of the Gihon Spring were shunted through this conduit, called Channel II, which runs south along the Kidron Valley. Up to 15 feet deep in places, the channel was cut into the rock from ground level. The top of the channel was sealed with huge boulders, thrown into the channel from above and trapped by the stone walls, which are slightly concave at top.