What was Warren’s shaft, if it wasn’t used to draw water? The diagram provides a cutaway view of the shaft in relation to the Gihon Spring, ancient Jerusalem’s source of water. It is now believed that the shaft, probably a natural feature formed by dissolution, was only accidently discovered in the eighth century B.C. by workers expanding a tunnel that led to the spring. Reich and Shukron recently excavated two large towers that they believe guarded the spring and a nearby pool. In their view, Warren’s Shaft played no role in supplying Jerusalem with water.