Joseph's or Yusif's Well
Joseph's, or Yusif's Well is located in the Citadel near the al-Nasir Mosque. It was constructed by crusade prisoners by order of Salah ad-Din in 1183, to insure the Citadel's water supply in the event of a siege. It plunges 97 feet to the level of the Nile, and water was lifted using two pumping stations. A spiral staircase with observation windows winds around the exterior of the well.