Where was the mythical Fountain of Youth located according to the Spanish explorer Ponce de León?

The Fountain of Youth is a spring that supposedly restores the youth of anyone who drinks or bathes in its waters. Tales of such a fountain have been recounted across the world for thousands of years, appearing in writings by Herodotus (5th century BCE), the Alexander romance (3rd century CE), and the stories of Prester John (early Crusades, 11th/12th centuries CE). Stories of similar waters were also evidently prominent among the indigenous peoples of the Caribbean during the Age of Exploration (early 16th century), who spoke of the restorative powers of the water in the mythical land of Bimini.

The legend became particularly prominent in the 16th century, when it became attached to the Spanish explorer Juan Ponce de León, first Governor of Puerto Rico. According to an apocryphal combination of New World and Eurasian elements, Ponce de León was searching for the Fountain of Youth when he traveled to what is now Florida in 1513.