The Fort Matanzas National Monument is the obvious day trip from St. Augustine itself — 14 miles south, accessible by free NPS ferry. The Timucuan Ecological and Historic Preserve north of Jacksonville protects one of the largest undisturbed estuaries on the US Atlantic coast and includes Fort Caroline, site of the 1565 French colony that Menéndez destroyed when he founded St. Augustine. Amelia Island, 45 minutes north, has an excellent stretch of beach and its own historic district at Fernandina Beach.