The famous well of Mecca.
According to Muslim legend, Zamzam was opened by the angel Gabriel to provide for Hagar and Ismaʿil, who were in danger of dying of thirst after Abraham deposited them in what was then an un-populated desert valley. History suggests that it was the coexistence of this well and the adjacent shrine (Kaʿba) that led to the emergence of Mecca as an important commercial and cultural center in pre-Islamic Arabia. For centuries Muslims have cherished the brackish water of Zamzam as sacred and have sought to benefit from its reputed blessings. To this day, pilgrims to the Meccan sanctuary descend the enclosed staircase to the well and either draw water for themselves to drink, or bottle it and take it home for a relative or friend who is ill.
see also kaʿba.