The Mae Sa snake farm of Chiangmai was where John Rambo was employed for an unspecified number of years as the snake catcher.
It was signifigant because it was a real business and the only known instance where John Rambo has been seen working for money at a job. The owners are very proud to have been featured on a popular worldwide film and have signs around the business about how the movie was filmed there.
The farm was a real establishment and not just a film set. The deejay who announces the snakes and how dangerous they are was a real person and is still employed there to this day. His name was Mr. Wasawat Panyarat. The snake fighter was also an employee and his name is Mr. Kammul Kawtep. The cobras seen in the film are real and venomous, so the snake fighter was in real danger and not just an actor for the film.