This State Forest is closer to "the city" than I would prefer, but unlike nearby Wekiwa State Park, the State Forest is relatively unknown, and undeveloped. There is a backpacking trail system with primitive camping permitted outside of hunting season.

I have hiked part of this trail network in the buff with no problems. By going during weekdays in the warmer months (the non hunting season months), you should be able to backpack and camp naked by excercising reasonable precautions (be dressed near roads or parking areas, carry shorts or a towel, etc).