The Big Creek Greenway is a paved multi-use trail that runs roughly eight miles along Big Creek through Alpharetta and Roswell — wooded, mostly flat, popular with cyclists, joggers, and stroller-pushing parents. The trail crosses the creek on a series of wooden bridges and passes through patches of forest that feel surprisingly remote for a suburban setting.
Multiple access points and parking lots run along the route. The full out-and-back is around sixteen miles and serious; an hour's wander from any access point is enough to get a feel for the trail and the surrounding woods.