Getting there: Go north on US 411 or I-75 to GA 52. Head east eight miles past Chatsworth to the park.
Contact: Fort Mountain State Park at (706) 695-2621, or www.gastateparks.org.
Regulations: All mountain bikers must pay a $2 daily fee and get a permit.
Extra treats: The mountain bike loops don't go by the old fort wall, so you'll want to hike the 1.8 mile (round-trip) trail past the wall, which features a jaw-dropping overlook and an old stone tower. No matter how tired your kids are, they'll revive at the lake's sandy swimming area, where they can build their own castles in the sky.