There's nothing much left, nothing at all, really, but here's a video filmed on what stands on the land where the old 40 Acres was, back in the glory days of television.

"In 1976 the old 40 acre backlot was demolished when it was sold for development into an industrial park. It was on this lot where the outdoor set for Mayberry, NC, once existed... It is located in Culver City, California at the foot of Blair Hill in the Baldwin Hills. Ballona Creek was the border on the south side off of Jefferson Blvd. Today, nothing is left of the old backlot, everything is gone..."

http://youtu.be/YDg8Ui8aR40

This is a nice one, 40 Acres helicopter fly over as "They are just starting to build Andy's house for the Andy Griffith Show.":

http://youtu.be/zPLhQl9ZLrM

And this one, some Star Trek & Untouchables footage showing downtown Mayberry:

http://youtu.be/rUQ9h_Gy70E