After abandoning Charlesfort in 1562, the French returned two years later and built a second secret fort in Spanish Florida named Fort Caroline.
In 1562, Jean Ribault set a marble column on a good spot for a fort at the mouth of the St. Johns River near Jacksonville. In 1564, the French sent René Laudonnière and a group of 300 Protestant settlers to build a settlement there so they could attack Spanish ships and legitimize their claim to Spanish Florida.
When Laudonnière arrived, he found the stone column and realized that the local Timucuan Indians had revered it. They built a remarkable large triangular-shaped fort which was drawn by the expedition artist, Jaques Le Moyne. For decades, the drawing has intrigued historians and archaeologists who have searched for its remains several times. But so far it has eluded everyone.
However, you can visit the Fort Caroline National Monument near Jacksonville, where the National Park Service used Le Moyne’s drawing to build a replica which is open to the public.