You can access this campsite by various means, but do your research and save yourself as many steps, because make no mistake, this is a serious hiking trail (a mile to a mile and a half, depending on route) up to the Fire Tower.
Part of the Appalachian Train, once you park your car or hike in, you'll make your way uphill over crude-cut rocks, tree roots, and muddy, narrow paths. Hiking poles are strongly recommended. The path down is just as treacherous as the path up, as moisture from the mountain drips down over craggy footholds.
While the path is popular with hikers, anyone camping should consider using a very small pack, especially since some of the trails have nothing but a chasm on one side.
Once you make it to the Fire Tower, however, all is forgiven. The site from the bottom is breathtaking, and you can see, well, forever. Heading up the tower (the very top is closed to visitors and mothballed), you get an almost full 360º panorama of the surrounding valleys and mountains.
The camp site itself is very rustic, no amenities other than a rock fire ring, and does not face the vistas. There's a weak LTE signal at the top, but be prepared to lose your signal along the way.
Side note: I came through the Coweeta Hydrological Laboratory, which has numerous signs posted that you cannot camp there. However, it's part of the larger National Forest and it's not exactly clear where camping begins to be allowed, as there were several rustic sites along the trail at the upper end.
If you do come driving through the Coweeta Hydrological Laboratory path, be prepared for narrow, steep gravel lanes. And keep in mind that if you do park your car on one of the (few) spaces available, you're going to be very far from it, and the site didn't appear to be patrolled in any way.