Ten Mile Creek Natural area in St. Lucie county covers 8 acres of old Florida. The walk along the path takes about 20 minutes, and leads you through at least two different natural landscapes - the hydric hammock and the floodplain forest. Several small bridges cover narrow streams that are surprisingly deep. There's also plenty of wildlife, including monster grasshoppers. (Okay, they weren't really huge, I just have an aversion to orange grasshoppers.) It's a fairly rugged path for the area, with no paving or railings, and climbs up and down sandy dunes - it's not real rough, but if you're looking for a simple leisurely stroll, you'd be best at one of the...less "natural" areas nearby.
The official address of the natural area is "near 3600 Gordy Road". The address I've listed takes you right to the parking lot.
3525 Gordy Rd
Fort Pierce FL 34945