Grayton Beach State Park is located off CR 30A (runs along Hwy. 98) between Destin and Panama City Beach. It is a very beautiful location and you can find something for everyone – swimming, beachcombing, hiking, kayaking, fishing and bicycling. This area is very popular for bicycling, so be mindful of them!
Entrance is just $5 for a vehicle (up to 8 people). They even have cabins available at this park.
For more information, visit: http://www.floridastateparks.org/graytonbeach