The Castillo de San Marcos was built by the Spanish to protect against attacks from the British. They began construction in 1668 and finished the fort in 1672. The fort was originally controlled by the Spanish, then by the British, the Spanish (again) and finally was handed over to the United States in 1819 when Spain yielded Florida to the United States.
The name most often associated with the Fountain of Youth is that of Ponce de León. There is a statue of him located in the Fountain of Youth National Archaelogical Park in St. Augustine. However, Ponce de León was not the first Spaniard to write of this legend, and he wasn't associated with the legend until after his death. The Fountain of Youth was written about by explorers like Gonzalo Fernández de Oviedo (1535), Francisco López de Gómara (1551) and Hernando D'Escalante Fontaneda (1575). Ponce de León never found the fountain of youth, but he did make an important contribution to the exploration of the New World when he claimed "la Florida" for the king of Spain. Although the site in St. Augustine isn't the real Fountain of Youth, many people (including Señorita Payne) drink from the spring.
Visit these sites to learn more about St. Augustine and its attractions: