Gihon Spring

Gihon Spring (Hebrew: מעיין הגיחון) 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. One of the world's major intermittent springs – and a reliable water source that made human settlement possible in ancient Jerusalem – the spring was not only used for drinking water, but also initially for irrigation of gardens in the adjacent Kidron Valley, which provided a food source for the ancient settlement. The spring rises in a cave 20 feet by 7, and is located 586 yards (535 m) northwards of the Pool of Siloam. Being intermittent, it required the excavation of the Pool of Siloam, which stored the large amount of water needed for the town when the spring was not flowing. Before the water table declined due to modern overpumping, the spring used to flow three to five times a day in winter, twice daily in summer, and once daily in autumn. This peculiarity is accounted for by the supposition that the outlet from the reservoir is by a passage in the form of a siphon. It has the largest output of water in the area – 600,000 cubic meters of water a year (compared to 125,000 cubic meters for the Lifta spring in West Jerusalem). The spring is under the control of the Israeli organization Ir David Foundation ("El'ad"); it is sometimes used by Jewish men as a sort of ritual bath (mikvah).