Rock City is an attraction located on the top of Lookout Mountain near Chattanooga. It is essentially a mountaintop trail lined with gardens, unusual rock formations and various things of interest.
Perhaps you've seen the slogan "See Rock City" painted on a barn somewhere in your travels? It's a pretty famous american image and was used to promote Rock City. Over 900 barns in 19 states were patinted.
Too much to see at Rock City to list here, but take a look through the photos and you'll get a glimpse of much of what Rock City has to offer. If you ever find yourself in the area and have some extra time on your hands, Rock City would be a good choice for a visit.