Warren's Shaft is a vertical shaft next to the Gihon Spring, the main source of water of Bronze and Iron Age Jerusalem, discovered in 1867 by British engineer, archaeologist and military officer Charles Warren. The term is currently used in either a narrower, or a wider sense:In the narrower, initial sense, Warren's Shaft is the almost vertical natural shaft leading down to a pool fed by the Gihon Spring. In the wider sense, as the Warren's Shaft system, it is the Bronze Age water system allowing protected access from the city to the Gihon Spring.

Gihon Spring or Fountain of the Virgin, also known as Saint Mary's Pool, is a spring in the Kidron Valley. It was the main source of water for the Pool of Siloam in Jebus and the later City of David, the original site of Jerusalem.