Nocatee is a master planned community that sits inland, between St. Augustine and Jacksonville. This is a very pleasant area for running. The best option is to run on the wide paths of the 5,000 acres of village-like neighborhoods. This fitness trails map has suggestions for numerous loops, with notes on sights along the way. One can put together 10+ miles of off-road, non-overlapping running.
For something more rugged, head over to the Nocatee Preserve, which encompasses 2,400 acres of wildly beautiful land fronting a 3.5-mile stretch of the Intracoastal Waterway known as the Tolomato River. There’s a nature/greenway trail that stretches for 3.5 miles one-way, starting off Davis Park Rd. near the Ponte Vedra High School and heading south. It’s a dirt trail than can be grassy in spots and sandy in spots. Bring bug spray!