Indian Shoals Falls is a 15-foot waterfall located along an unnamed tributary of the Apalachee River, just downstream from a bridge along Indian Shoals Road. Although this waterfall is evident on satellite imagery, I've never found a photo of it and you won't see much from the road bridge. Indian Shoals Falls lies on private property and is closed to public access. 

To learn about more waterfalls in the Atlanta metro area, see chapter 11 in Mark Ozboyd's "Waterfalls of Georgia" guidebook.