Although supposedly in relatively flat Atlanta, there are mountains in the background rising several thousand feet in numerous shots. Also, the scene with the father and his sons at the train park was clearly shot at the "Griffith Park & Southern Railroad", in Griffith Park, near Burbank, CA.
At around 14 minutes and 45 seconds before the series ends, an outside shot of Vince's Gym is shown. This gym is located in Studio City, California and was owned by Vince Gironda. He was known as the Iron Guru, and was a bodybuilding and fitness trainer of the stars at his famous gym. The gym was active from 1948 through 1997.
In exterior shots the brown California mountains are clearly visible. There are no mountains in Atlanta.