Looking for a day-trip just outside Duval County? Fort Clinch State Park, located in Fernandina Beach, Florida, is a great place for everyone: kids ( the day I went there was a homeschooling group there), families, couples (a perfect place for a photo shoot), and history buffs.
The park hours are from 8am to sunset every day of the year. Entrance to the park is $6 a car. Entrance to the Fort is $2 a person. Here is the address if you are planning a visit:
Fort Clinch State Park
2601 Atlantic Avenue
Fernandina Beach, Florida 32034