Bayard Conservation Area, John P. Hall, Sr. Tract, near Green Cove Springs in North Central Florida is quite an outdoor gem. Near the Shands Bridge crossing of the St. John's River, it provides beautiful and well-maintained trails for biking, hiking, camping, and horseback riding. The trails seem almost limitless, weaving through over 10,000 acres, all very easy to follow by white, red, yellow, and blue markers. The paths are mostly well-cleared so there isn't as much trouble from biting insects as some other trails. The scenery changes dramatically based on elevation and distance from the river, with plenty of opportunities for birding and spotting other wildlife.
I hiked here for several hours following a controlled burn, and the contrast between green and burned brown portions of the area provided some neat contrast for outdoor photos. This land is maintained by the St. Johns River Water Management District.