The Fountain of Youth is a mythical spring which allegedly restores the youth of anyone who drinks or bathes in its waters. Tales of such a fountain have been recounted around the world for thousands of years, appearing in the writings of Herodotus, in the Alexander romance, and in the stories of Prester John. Stories of similar waters also featured prominently among the people of the Caribbean during the Age of Exploration ; they spoke of the restorative powers of the water in the mythical land of Bimini. Based on these many legends, explorers and adventurers looked for the elusive Fountain of Youth or some other remedy to aging, generally associated with magic waters. These waters might have been a river, a spring or any other water-source said to reverse the aging process and to cure sickness when swallowed or bathed in.

A spring is a natural exit point at which groundwater emerges out of the aquifer and flows onto the top of the Earth's crust (pedosphere) to become surface water. It is a component of the hydrosphere, as well as a part of the water cycle. Springs have long been important for humans as a source of fresh water, especially in arid regions which have relatively little annual rainfall.