Just a couple of postings ago I ran a photo of Floyd's Barber Shop making a cameo appearance in Star Trek:
Well, of course it was that Floyd's. The Desilu back lot in Culver City was used for, well, everything. In fact, the crossover went the other way, too.
Here's a picture of Ronny Howard (Opie Taylor, of course) riding his bicycle down Mayberry's main street, past the grocery and (just past it, out of frame to the right) a TV repair shop and Floyd's. But that larger building in the distance, the one that blue car is parked in front of? It's Edith Keeler's 21st Street Mission, still dressed for Star Trek instead of its usual role on the Andy Griffith Show, the Grand Theater. Well, I guess Otis had to sleep somewhere when he wasn't under arrest.
The pictures come from the RetroWeb 40 Acres website, a tour of what was originally called the Pathe 40 Acre Ranch (though it was really only 27 acres). De Mille used it for King of Kings. RKO used it for King Kong. Selznick used it for Gone With The Wind. (You may already know that the King of Kings and King Kong sets were destroyed for the "burning of Atlanta" scenes.) The Atlanta Depot was still there when Superman, Andy Griffith, Star Trek and Hogan's Heroes were filming there. So if every town in every TV show and movie looked alike, well, there's a reason. They were all filmed in "Atlanta."
The location given at Wikipedia makes the area easy to find, but if you're an old movie buff, there's really no point. There's nothing to see. It's industrial now.