Very large trail network with lots of different styles available. You can find singletrack, fire roads, good uphills and downhills. There is no set route, just start riding and find your way.
Take exit 150 East off I-95 and drive straight through the Marine Corps Base gate. Continue straight to Purvis Road. Turn right on Purvis road and drive to the Child Development Center (on left). Trail begins in the back left corner of the parking lot. ID required to drive on base.
http://www.singletracks.com/item.php?c=1&i=1989