Incredible. I found out about this a few years ago and finally got a chance to go today. What an AMAZING experience! If anyone is anywhere near Nazareth, PA I would highly suggest going.
The factory tour normally lasts an hour I think but there were only 3 people on the tour and we were really into it so I think the guy made it longer for us. I got to see the entire process from start to finish. It's unreal what goes into it. And the workers on the floor seem like they really love what they're doing. Great company.
Then the museum was surreal. There was a timeline of when the first Martin was made all the way up through the present. All kinds of vintage guitars were on display. Everything from Elvis Presley and Ricky Nelson right up to Dave's DM3MD (what a treat to actually see one in person!!!).
There is also a visitor center where you can buy mdse and even play VINTAGE guitars in the back room!!! One was a Johnny Cash original. There are random pictures up of Martin players throughout history and I saw a great one of Dave that I would have bought in an instant if it were for sale. One I had never seen before.
I'm leaving out a lot of detail because you just have to see it all to believe it. What a trip this place is if you love guitars. I'm kicking myself for not bringing my camera.
Here's some info -