This Cobb County park has an out-and-back boardwalk and natural surface trail that follows Nickajack Creek. The trail’s northwest end connects to the Silver Comet Trail near Concord Road.
Near the west end of the trail stand the ruins of the Concord Woolen Mill. The mill originally opened in 1847, was burned by Sherman’s troops, after which it was rebuilt once and then again after a second fire in 1889. The mill was abandoned in 1916.  A “ghost frame” was added in 1996 to stabilize the ruins. Extensive in-depth information about the mill is available at the Concord Covered Bridge website.
Speaking of the Concord Covered Bridge, it is located nearby on Concord Road and is still in use for vehicular traffic.
Also known as: Heritage Park Trail
Address: 60 Fontaine Road, Mableton, GA 30126
Cost of admission: None
Governance: Cobb County
Acres: Approx. 110
Approximate miles of trails: 1.8 mile each way out-and-back
Hours: Sunrise to sunset
Miles from downtown Atlanta: 11
Cycling directions: There’s a trailhead along the Silver Comet Trail
Parking: Parking is available along the trailhead at Fontaine Rd. and Nickajack Rd. Alternatively, you can park at the Silver Comet Trail’s Concord Road trailhead and walk southeast on the Silver Comet for about 1/3 mile to the Heritage Park trailhead.
Trailhead(s): There is one trailhead near the intersection of Fontaine Rd. and Nickajack Rd., and a second trailhead along the Silver Comet Trail.
Trail surface: Natural and boardwalk
Blazes/markings: None, but the trail is wide enough to be clear
Dogs allowed: Yes
Guidebook mentions: Chapter 25 in Hiking Atlanta's Hidden Forests (1st edition)
Restrooms (closed when below freezing)
For more photos, see my flickr album.